ER is an American medical drama television series created by novelist and medical doctor Michael Crichton that aired on the NBC network from September 19, 1994 to April 2, 2009, lasting for 15 seasons and 331 episodes. It was produced by Constant c Productions and Amblin Television, in association with Warner Bros. Television. ER follows the inner life of the emergency room (ER) of fictional County General Hospital in Chicago, Illinois, and various critical issues faced by the room's physicians and staff.
The show was the longest-running primetime medical drama in American television history, until "Grey's Anatomy" surpassed it in 2019.
It won 23 Primetime Emmy Awards, including the 1996 Outstanding Drama Series award, and received 124 Emmy nominations, making it the most nominated drama program in history.
In total, "ER" has won 116 awards in total, including the Peabody Award while the cast earned four Screen Actors Guild Awards for "Outstanding Ensemble Performance in a Drama Series."
In 1974, author Michael Crichton wrote a screenplay based on his own experiences as a resident physician in a busy hospital emergency room, but the screenplay went nowhere and Crichton went on to focus on other topics. In 1990, he published the novel "Jurassic Park" and in 1993, he began a collaboration with director Steven Spielberg on the film adaptation of the book. Crichton and Spielberg then turned to "ER," but decided to film the story as a two-hour pilot for a television series rather than as a feature film. Spielberg's Amblin Entertainment provided John Wells as the show's executive producer. The script used to shoot the pilot was virtually unchanged from what Crichton had written in 1974. The only substantive changes made by the producers in 1994 were that the Susan Lewis character became a woman and the Peter Benton character became an African-American & the running time was shortened by about 20 minutes in order for the pilot to air in a two-hour block on network TV. Because of a lack of time and money necessary to build a set, the pilot episode of ER was filmed in the former Linda Vista Hospital in Los Angeles (an old facility that had ceased operating in 1990). A set modeled after Los Angeles County General Hospital's emergency room was built soon afterward at the Warner Bros. studios in Burbank, California although the show makes extensive use of location shoots in Chicago, most notably the city's famous "L" train platforms.
Warren Littlefield (who was running NBC Entertainment at the time) was impressed by the series, saying: "We were intrigued, but we were admittedly a bit spooked in attempting to go back into that territory a few years after St. Elsewhere." After Spielberg had joined as a producer, NBC ordered six episodes of the series. According to Littlefield, "ER" premiered opposite a Monday Night Football game on ABC and did surprisingly well. Then we moved it to Thursday and it just took off." The show's success surprised the networks and critics alike as David E. Kelley's new medical drama "Chicago Hope" was expected to crush the new series.
Spielberg left the show after one year as a producer, having made one critical decision with lasting effects: the Carol Hathaway character (who died at the end of the original pilot episode script) was retained. Crichton remained executive producer until his death in November of 2008 (although he was still credited as one throughout that entire final season). Wells (the series' other initial executive producer) served as showrunner for the first three seasons. He was one of the show's most prolific writers and became a regular director in later years.
Lydia Woodward was a part of the first season production team and became an executive producer for the third season. She took over as showrunner for the fourth season while Wells focused on the development of other series including Trinity, Third Watch and The West Wing. Woodward left her executive producer position at the end of the sixth season, but she continued to write episodes throughout the series' run.
Joe Sachs (who was a writer and producer of the series) believed keeping a commitment to medical accuracy was extremely important, saying:
"We'd bend the rules but never break them. A medication that would take 10 minutes to work might take 30 seconds instead. We compressed time. A 12- to 24-hour shift gets pushed into 48 minutes. But we learned that being accurate was important for more reasons than just making real and responsible drama."
Woodward was replaced as showrunner by Jack Orman. Orman was recruited as a writer-producer for the series in its fourth season after a successful stint working on "CBS's JAG." He was quickly promoted and became an executive producer and showrunner for the series' seventh season. He held these roles for three seasons before leaving the series at the end of the ninth season. Orman was also a frequent writer and directed three episodes of the show. David Zabel served as the series' head writer and executive producer in its later seasons. He initially joined the crew for the eighth season and became an executive producer and showrunner for the twelfth season onward. Zabel was the series' most frequent writer, contributing to 41 episodes. He also made his directing debut on the series. Christopher Chulack was the series' most frequent director and worked as a producer on all 15 seasons. He became an executive producer in the fourth season, but occasionally scaled back his involvement in later years to focus on other projects. Other executive producers include writers Carol Flint, Neal Baer, R. Scott Gemmill, Dee Johnson, Joe Sachs, Lisa Zwerling and Janine Sherman Barrois. Several of these writers and producers had extensive background in emergency medicine. Joe Sachs was a regular emergency attending physician while Lisa Zwerling and Neal Baer had pediatrics backgrounds. The series' crew was recognized with awards for writing, directing, producing, film editing, sound editing, casting and music.
Cast and Characters
- Main article: Cast and Characters
The original starring cast consisted of Anthony Edwards as Dr. Mark Greene, George Clooney as Dr. Doug Ross, Sherry Stringfield as Dr. Susan Lewis, Noah Wyle as medical student John Carter and Eriq La Salle as Dr. Peter Benton. As the series continued, some key changes were made: Nurse Carol Hathaway (played by Julianna Margulies) who attempts suicide in the original pilot script was made into a regular cast member. Ming-Na debuted in the middle of the first season as medical student Jing-Mei "Deb" Chen, but didn't return for the second season. She returned in the 10th episode of the sixth season. Gloria Reuben and Laura Innes would join the series as Physician Assistant Jeanie Boulet and Dr. Kerry Weaver respectively, by the second season.
In the third season, a series of cast additions and departures that would see the entire original cast leave over time began. Sherry Stringfield was the first to exit the series, reportedly upsetting producers who believed she wanted to negotiate for more money, but Stringfield did not particularly care for "fame." She would return to the series from 2001 until 2005. George Clooney departed the series in 1999 to pursue a film career and Julianna Margulies exited the following year in 2000. Season eight saw the departure of Eriq La Salle and Anthony Edwards when Benton left County General and Mark Greene died from a brain tumor. Noah Wyle left the series after season 11 in order to spend more time with his family, but would return for two multiple-episode appearances in the show's final seasons. Goran Visnjic as Dr. Luka Kovac, Maura Tierney as Dr. Abby Lockhart, Alex Kingston as Dr. Elizabeth Corday and Paul McCrane as Dr. Robert Romano, all joined the cast as the seasons went on. In the much later seasons, the show would see the additions of Mekhi Phifer as Dr. Greg Pratt, Scott Grimes as Dr. Archie Morris, Parminder Nagra as Dr. Neela Rasgotra, Shane West as Dr. Ray Barnett, Linda Cardellini as nurse Samantha Taggart, John Stamos as intern Tony Gates and Angela Bassett as Dr. Catherine Banfield.
In addition to the main cast, ER featured a large number of frequently seen recurring cast members who played key roles such as paramedics, hospital support staff, nurses and doctors.
ER also featured a sizable roster of well-known guest stars, some making rare television appearances, who typically played patients in single episode appearances or multi-episode arcs.
Following the broadcast of its two-hour pilot movie on September 19, 1994, ER premiered Thursday, September 22, 1994 at 10:00. It remained in the same Thursday time slot for its entire run.
The show is NBC's third longest-running drama, after Law & Order and Law & Order: Special Victims Unit and the longest-running American primetime medical drama of all time
On April 2, 2008, NBC announced that the series would return for its fifteenth season.
The fifteenth season was originally scheduled to run for 19 episodes before retiring with a two-hour series finale to be broadcast on March 12, 2009, but NBC announced in January 2009 that it would extend the show by an additional three episodes to a full 22-episode order as part of a deal to launch a new series by John Wells titled Police, later retitled "Southland."
The final episode of ER aired on April 2, 2009; the two-hour episode was preceded by a one-hour retrospective special. The series finale charged $425,000 per 30-second ad spot, more than three times the season's rate of $135,000.
From season four to season six, the series cost a record-breaking 13 million dollars. TNT also paid a record price of $1 million an episode for four years of repeats of the series during that time.
The cost of the first three seasons was 2 million per episode and seasons 7 to 9 cost 8 million dollars per episode.
A typical episode centered on the ER, with most of the scenes set in the hospital or surrounding streets.
In addition, most seasons included at least one storyline located completely outside of the ER, often outside of Chicago. Over the span of the series, stories took place in the Democratic Republic of The Congo, France, Iraq and Sudan.
Beginning in season nine, storylines started to include the Democratic Republic of the Congo, featuring Dr. Kovac, Dr. Carter and Dr. Pratt.
“We turned some attention on the Congo and on Darfur when nobody else was. We had a bigger audience than a nightly newscast will ever see, making 25 to 30 million people aware of what was going on in Africa,” ER producer John Wells said. “The show is not about telling people to eat their vegetables, but if we can do that in an entertaining context, then there’s nothing better.”
The series also focused on sociopolitical issues such as HIV and AIDS, organ transplants, mental illness, racism, human trafficking, euthanasia, poverty and gay rights.
The Africa episodes of ER were discussed in a scholarly article by Julie Cupples and Kevin Glynn published in the Annals of the Association of American Geographers in 2013.
Other episodes used more creative formats, such as the 1997 live episode "Ambush" performed twice; once for the east coast broadcast and again three hours later for the west coast and 2002's "Hindsight" which ran in reverse time as it followed one character, Dr. Luka Kovac through the tragic events of one Christmas Eve shift and the Christmas party that preceded it.
|Season||Episodes||Network||First air date||Last air date|
|Season 1||25||NBC||September 19, 1994||May 18, 1995|
|Season 2||22||September 21, 1995||May 16, 1996|
|Season 3||22||September 26, 1996||May 15, 1997|
|Season 4||22||September 25, 1997||May 14, 1998|
|Season 5||22||September 24, 1998||May 20, 1999|
|Season 6||22||September 30, 1999||May 18, 2000|
|Season 7||22||October 12, 2000||May 17, 2001|
|Season 8||22||September 27, 2001||May 16, 2002|
|Season 9||22||September 26, 2002||May 15, 2003|
|Season 10||22||September 25, 2003||May 13, 2004|
|Season 11||22||September 23, 2004||May 19, 2005|
|Season 12||22||September 22, 2005||May 18, 2006|
|Season 13||23||September 21, 2006||May 17, 2007|
|Season 14||19||September 27, 2007||May 15, 2008|
|Season 15||22||September 25, 2008||April 2, 2009|
- See also Third Watch
The episode "Brothers and Sisters" (first broadcast on April 25, 2002) begins a crossover that concludes on the Third Watch episode "Unleashed", in which Susan enlists the help of Officers Maurice Boscorelli and Faith Yokas to find her sister and niece.
ER was filmed in 1.78:1 widescreen from the start, even though it was not broadcast in widescreen until the seventh season, when it began appearing in the 1080i HD format. Since the sixth episode of season 7, it has appeared in letterbox format when in standard definition. As a result, the U.S. DVD box set features the widescreen versions of the episodes, including those episodes originally broadcast in 1.33:1 (full frame) format. The episodes also appear in 1080i widescreen when rerun on TNT HD and Pop, though the first six seasons still run in full frame 1.33:1 on the digital TNT network. Only the live episode "Ambush" at the beginning of the fourth season and the title sequence for the first six seasons originated in the 1.33:1 aspect ratio.
In its first year, "ER" attracted an average of 19 million viewers per episode, becoming the years second most watched television show, just behind "Seinfeld."
In the following two seasons (1995-1997), it was the most watched show in North America.
For almost five years, the series battled for the top spot against "Seinfeld", but in 1998, "Seinfeld" ended and then "ER" became number one again.
The series finale attracted 16.4 million viewers.
The show's highest rating came during season 2 episode "Hell and High Water," with 48 million viewers and a 45% market share.
It was the highest for a regularly scheduled drama since a May 1985 installment of "Dallas" received a 46. The share represents the percentage of TVs in use tuned in to that show.
|Season||Season premiere||Season finale||Viewer
|1||September 19, 1994||May 18, 1995||#2||19.08|
|2||September 21, 1995||May 16, 1996||#1||21.10|
|3||September 26, 1996||May 15, 1997||#1||30.79|
|4||September 25, 1997||May 14, 1998||#2||30.2|
|5||September 24, 1998||May 20, 1999||#1||25.4|
|6||September 30, 1999||May 18, 2000||#4||24.95|
|7||October 12, 2000||May 17, 2001||#2||22.4|
|8||September 27, 2001||May 16, 2002||#3||22.1|
|9||September 26, 2002||May 15, 2003||#6||19.99|
|10||September 25, 2003||May 13, 2004||#8||19.04|
|11||September 23, 2004||May 19, 2005||#16||15.17|
|12||September 22, 2005||May 18, 2006||#30||12.06|
|13||September 21, 2006||May 17, 2007||#40||11.56|
|14||September 27, 2007||May 15, 2008||#54||9.20|
|15||September 25, 2008||April 2, 2009||#37||10.30|
Throughout the series' run, "ER" received positive reviews from critics and fans alike. It scored 80 on Metascore, meaning "generally favorable reviews" based on 21 critics. Marvin Kitman from Newsday gave the show a very positive review, saying: "It's like M*A*S*H with just the helicopters showing up and no laughs. E.R. is all trauma; you never get to know enough about the patients or get involved with them. It's just treat, release and move on". Richard Zoglin from Time stated that it's "probably the most realistic fictional treatment of the medical profession TV has ever presented".
Critical reactions for ER's first season were very favorable. Alan Rich, writing for Variety, praised the direction and editing of the pilot while Eric Mink, writing for the New York Daily News, said that the pilot of ER "was urban, emergency room chaos and young, committed doctors." However some reviewers felt the episodes following the pilot did not live up to it with Mink commenting that "...the great promise of the "E.R." pilot dissolves into the kind of routine, predictable, sloppily detailed medical drama we've seen many times before."
Because the show launching on NBC at the same time that CBS launched its own medical drama "Chicago Hope", many critics drew comparisons between the two. Eric Mink concluded that "ER" may rate more highly in the Nielsens, but "Chicago Hope" told better stories while Rich felt both shows were "riveting, superior TV fare." The Daily Telegraph wrote in 1996: "Not being able to follow what on earth is going on remains one of the peculiar charms of the breakneck American hospital drama, ER".
In 2002, TV Guide ranked the series No. 22 on their list of "TV's Top 50 Shows", making it the second highest ranked medical drama on the list (after "St. Elsewhere" at #20). Also, the season 1 episode "Love's Labor Lost" was ranked No. 6 on "TV Guide's 100 Greatest Episodes of All-Time" list having earlier been ranked #3. The show also placed No. 19 on Entertainment Weekly's "New TV Classics" list. British magazine Empire ranked it No. 29 in their list of the "50 Greatest TV Shows of All Time" and said the best episode was the season two episode "Hell and High Water" where "Doug Ross (George Clooney) saves a young boy from drowning during a flood."
In 2012, "ER" was voted "Best TV Drama" on ABC's 20/20 special episode "Best in TV: The Greatest TV Shows of Our Time". In 2013, TV Guide ranked it No. 9 in its list of The 60 Greatest Dramas of All Time and No. 29 in its list of the "60 Best Series". During that same year, the Writers Guild of America ranked "ER" No. 27 in its list of the "101 Best Written TV Series Of All Time."
The series has been nominated for 375 industry awards and has won 116.
It won the George Foster Peabody Award in 1995 and won 22 of the 124 Emmy Awards for which it was nominated.
It also won the People's Choice Award for "Favorite Television Dramatic Series" every year from 1995 to 2002.
Over the years, "ER" has been nominated for and/or won numerous other awards including Screen Actors Guild Awards, Image Awards, GLAAD Media Awards and Golden Globe Awards, among others.
Warner Home Video (Warner Archive Collection) has released all 15 seasons of the series in regions 1, 2 and 4 on DVD.
|DVD name||Ep#||Release dates|
|Region 1||Region 2||Region 4|
|ER: The First Season||25||August 26, 2003||February 23, 2004||April 28, 2004|
|ER: The Second Season||22||April 27, 2004||July 26, 2004||July 15, 2004|
|ER: The Third Season||April 26, 2005||January 31, 2005||December 16, 2004|
|ER: The Fourth Season||December 20, 2005||May 16, 2005||April 27, 2005|
|ER: The Fifth Season||July 11, 2006||October 24, 2005||November 15, 2005|
|ER: The Sixth Season||December 19, 2006||April 3, 2006||May 5, 2006|
|ER: The Seventh Season||May 15, 2007||September 18, 2006||October 3, 2006|
|ER: The Eighth Season||January 22, 2008||July 16, 2007||September 6, 2007|
|ER: The Ninth Season||June 17, 2008||October 29, 2007||October 31, 2007|
|ER: The Tenth Season||March 3, 2009||January 28, 2008||May 7, 2008|
|ER: The Eleventh Season||July 14, 2009||April 21, 2008|
|ER: The Twelfth Season||January 12, 2010||September 15, 2008||October 1, 2008|
|ER: The Thirteenth Season||23||July 6, 2010||November 3, 2008||April 29, 2009|
|ER: The Fourteenth Season||19||January 11, 2011||May 18, 2009||April 28, 2010|
|ER: The Final Season||22||July 12, 2011||September 21, 2009||October 12, 2010|
The first six DVD box sets of "ER" are unusual in the fact that they are all in anamorphic widescreen even though the episodes were broadcast in a standard 4:3 format. Only the live episode "Ambush" is not in the widescreen format.
In 1996, Atlantic Records released an album of music from the series' first two seasons, featuring James Newton Howard's theme from the series in its on-air and full versions.
The selections from the weekly scores were composed by Martin Davich (Howard scored the two-hour pilot, Davich scored all the subsequent episodes and wrote a new theme used from 2006–2009 until the final episode, when Howard's original theme returned) and songs used on the series.
- Theme From ER – James Newton Howard (3:02)
- Dr. Lewis And Renee (from "The Birthday Party") (1:57)
- Canine Blues (from "Make of Two Hearts") (2:27)
- Goodbye Baby Susie (from "Fevers of Unknown Origin") (3:11)
- Doug & Carol (from "The Gift") – composed by James Newton Howard and Martin Davich *(1:59)
- Healing Hands – Marc Cohn (4:25)
- The Hero (from "Hell And High Water") composed by James Newton Howard and Martin Davich (1:55)
- Carter, See You Next Fall (from "Everything Old Is New Again") (1:28)
- Reasons For Living – Duncan Sheik (4:33)
- Dr. Green and a Mother's Death (from "Love's Labor Lost") (2:48)
- Raul Dies (from "The Healers") (2:20)
- Hell And High Water (from "Hell And High Water") – composed by James Newton Howard and Martin Davich (2:38)
- Hold On (from "Hell And High Water") (2:47)
- Shep Arrives (from "The Healers") (3:37)
- Shattered Glass (from "Hell And High Water") (2:11)
- Theme From ER – James Newton Howard (1:00)
- It Came Upon A Midnight Clear – Mike Finnegan (2:30)
- An ER video game for Windows 2000 and XP was released in 2005.
- A book about emergency medicine based on the TV series called "The Medicine of ER: An Insider's Guide to the Medical Science Behind America's #1 TV Drama" was published in 1996. Authors Alan Duncan Ross and Harlan Gibbs M.D. have hospital administration and ER experience, respectively & are called fans of the TV show in the book's credits.
- The series is NBC's second longest-running drama (after "Law & Order") and at fifteen seasons, it is the longest-running American primetime medical drama.
- It is the most Emmy-nominated show in television history at 123 nominations.
- Due to a lack of time and money to build a set, the pilot episode of ER was filmed in the former Linda Vista Community Hospital in Los Angeles, an old facility that ceased operating as a medical center in 1990. The set for the pilot episode was a rundown hospital in East Los Angeles, California as they couldn't afford to build a proper set of their own. As the rooms were quite small, this necessitated the use of the Steadicam, which has since become the trademark of the show. Real members of the public (usually punk gangs) would often pull up outside, mistaking the set for the real thing.
- Carol Hathaway (Julianna Margulies) was supposed to be brain-dead from a suicide attempt in the first episode, but the character was revived for the series. For the first episode, she was credited as a guest star.
- Anthony Edwards was first choice to play the part of Dr. Mark Greene, but unfortunately, Edwards was committed to direct a feature film at the time the pilot was due to shoot, and was therefore unavailable. By sheer luck, his feature was pushed back and he was able to film the pilot instead.
- Actor Tony Todd was considered for the role of Dr. Peter Benton.
- Actor Todd Allen auditioned for the role of Dr. Mark Greene, but he appeared in an unaired pilot that season called "Frogmen".
- George Clooney had his first regular television role in a short-lived comedy series t called "E/R."
- Actress Lisa Zane tested for the part of Dr. Susan Lewis. She would later play a love interest for George Clooney's character named Diane Leeds.
- Anthony Edwards, Paul McCrane, Laura Innes and Eriq La Salle are the only cast members to direct episodes throughout the series' fifteen season run.
- Some of the operations in the series were dramatized versions of real-life operations. The writers scouted out hospitals around the Los Angeles area to get ideas for new episodes. An early episode in which a baby gets a coat hanger stuck in its throat was based on a real emergency in a Los Angeles hospital. However, the situation was dramatized by adding a scene where the baby bleeds profusely and required a tracheotomy (in real-life, they simply reached in and pulled the hanger out).
- Because the show could make only a couple of location shoots in Chicago each year, the exterior scenes would often have to be filmed in advance of the rest of the episode's shoot back in Los Angeles. Sometimes a scene for an episode would have to be shot before it was even written. A famous example of this is the final scene in "Love's Labor Lost" when Dr. Greene cries on the El Train. Director Mimi Leder could only give Anthony Edwards a brief description of what was to occur and told him to "find it," "it" being the sadness Greene was experiencing.
- Julianna Margulies originally read for the part of Dr. Mark Greene's wife. The role was eventually given to actress Christine Harnos.
- Although mostly shot at Warner Brother's Burbank soundstages, the cast and crew usually made at least two trips to Chicago each season to shoot realistic exterior scenes for several episodes (which include many familiar Chicago landmarks). These scenes are normally shot on early Sunday mornings to avoid disrupting traffic.
- Matthew Watkins (who plays Dr. Benton's deaf son, Reese) is deaf in real-life.
- The first four episodes of the show all began the same way, with one of the doctors being awakened early in the morning from "Exam 8" at the end of the hallway in this order: Greene (Pilot), Lewis (Day One), Benton (Going Home), Carter (Hit and Run). This became a recurring motif throughout the run of the series and the 200th episode began this way as well. Of the original five doctors, Ross (George Clooney) was the only one who was never shown sleeping in Exam 8.
- Prior to taking the role of med student Lucy Knight, Kellie Martin called herself "One Take Kellie" as she was not used to the medical jargon that her character had to say; she claimed that it once took her 12 takes to correctly pronounce "renal vein thrombosis."
- The producers wanted the character of Carol Hathaway to switch from being a nurse to a doctor and even filmed episodes of her starting medical school. Julianna Margulies objected to the idea, saying that her character would be so proud of being a nurse she would never want to change, so the idea was dropped. Years later, the character of Abby Lockhart (played by Maura Tierney) did go from being a nurse to a doctor.
- Goran Visnjic named his own character after the writers were unable to develop an appropriately Croatian name. The character is named for his nephew (Luka) and his best friend (Kovac).
- Doug Ross frequently hung his head low, appearing ashamed or thoughtful or privately amused, depending on the scene. This wasn't just an element of the character: George Clooney had taken to writing his lines on papers, sheets and other props (especially the complicated medical terminology).
- Out of all the numerous celebrity guest stars on the series, only Sally Field and Ray Liotta have won Emmys for their roles.
- The character played by Ming-Na Wen was addressed only as Deborah Chen when she first appeared in the series in 1995. When she returned to the show in 2000, she took to a more traditional name, Jing-Mei (which was also the name of the character Ming-Na played in "The Joy Luck Club").
- If anything had gone wrong during the broadcast of the live episode (such as a technical failure or forgotten dialogue), the producers had additional actors ready to improvise a scene that would have been inserted to cover. This contingency was never used.
- The basketball hoop found outside of the ambulance bay of the ER was actually George Clooney's idea. Apparently, Clooney liked to unwind in-between takes by shooting some hoops. Because of this, it was placed in an area of the Warner Brothers (in Burbank, California) studio lot where it could be picked up by the camera. It quickly became a part of the series.
- In the live broadcast of 1997, the baseball game that George Clooney's character is watching in the break room was the Cubs-Astros game (which also being broadcast live that night on WGN).
- Casting Director John Frank Levey originally suggested Michael Beach for the role of Dr. Peter Benton, but John Wells felt Beach didn't complete the ensemble and chose Eriq La Salle instead. Beach eventually appeared on "ER "as Al Boulet (the ex-husband of Jeanie Boulet). He would also later be cast as a regular in another John Wells-produced series "Third Watch."
- Gloria Reuben (Jeannie Boulet) and Erik Palladino (Dave Malucci) left the show because they felt that their characters were being under-used. Kellie Martin (Lucy Knight) left the series when it became too painful to work in a medical show following the death of her sister.
- Alex Kingston announced in an interview in 2004 that her contract to return for an eighth year on the show was not renewed. She said she was told plots for her character had "run their course."
- Noah Wyle, Laura Innes and Alex Kingston are the only main credited actor and actresses to appear with every member of the main cast at one stage or another during the show's fifteen-year run.
- Desk clerk Frank (Troy Evans) always talks about life on the "force" as a Chicago police officer. In the first episode, he had an appearance as a police officer, who was shot and treated by the ER staff.
- Michael Crichton's original script took place in Boston Memorial Hospital. Dr. Mark Greene was "Richie Greene" in this version and Dr. Susan Lewis was "Beth Lewis." George Clooney's character was originally going to be called Tom Ross and Julianna Margulies was going to be called Barb Hathaway.
- Abby's full name is Abigail Marjorie Wyczenski Lockhart.
- Doctors Mark Green and Elizabeth Corday lived at 1211 Dupont Drive.
- Dr. Ray Barnett's band is called "Skunk Hollow".
- Dr. Carter's birth date is June 4, 1970. Noah Wyle's birth date is June 4, 1971.
- Dr. Carter's full name is John Truman Carter III.
- Dr. Romano (Paul McCrane) has a model of an Apollo Saturn V rocket in the background of his office. McCrane played astronaut Pete Conrad, commander of Apollo 12 in the HBO mini-series "From the Earth to the Moon".
- Firefighter Sandy Lopez (Lisa Vidal) was the first lesbian Latina primary or secondary character on a television series.
- After Laura Innes left the show in January 2007, NBC received some pressure from GLAAD to introduce more LGBT characters.
- The helicopter used for the show actually belongs to the University of Chicago Hospital. It is a 1989 AEROSPATIALE SA365N-1 DAUPHIN, registration number N365UC. As of 2017, this same helicopter is still in service with the university. The registration is valid through 2019.
- Glenne Headly was pregnant when she signed on to do her story arc as Dr. Abby Keaton in the third season. Originally, the writers floated the idea of writing the pregnancy into the show, but then decided that audiences would have difficulty accepting John Carter having a relationship with a heavily pregnant woman. In the later stages, Headly had to be photographed behind gurneys and in ill-fitting surgical scrubs to hide her bump.
- In one episode, Dr. Lewis admits that she's only familiar with the Walt Whitman poem "I Sing the Body Electric" because it appeared in song form in the movie "Fame". That song in that film was sung by Paul McCrane (Dr. Romano).
- Seasons seven of the series are the only seasons to not have a cast change.
- Laura Innes and Noah Wyle tied as the series' longest-appearing cast members, having appeared in thirteen out of fifteen seasons. Innes' character Dr. Kerry Weaver made her first appearance in season two, stayed on as a regular until the midpoint of Season thirteen, and appeared in two season fifteen episodes. Wyle's character Dr. John Carter was a regular from the start of season one, left the regular cast in the season eleven finale, had a multi-episode guest role in season twelve (for a story set in Darfur), and returned for several season fifteen episodes. Both were in the series finale and had a few scenes together.
- More performers (31) received Emmy nominations as lead, supporting, or guest actors and actresses on this show than did for any other series.
- The character of Dr. John Carter was named after the protagonist in the classic "John Carter: Man from Mars" pulp science fiction stories.
- Actor Vondie Curtis-Hall appeared on the show as two characters. In season one, he played a transsexual, (for which he was nominated for an Emmy) and in later episodes, he played Carla's husband, and fought Dr. Benton for custody of his son, Reese.
- George Clooney's cousin Miguel Ferrer, appeared as a guest star in the two-hour pilot episode and his aunt, Rosemary Clooney (Miguel Ferrer's mother) appeared in the second regular episode. Clooney shared scenes with neither of them.
- Of all the major characters, only Sherry Stringfield and Sharif Atkins have never been shown as patients in the ER.
- Season fourteen was supposed to be the series' final season, but the 2007-08 WGA strike left both the producers & NBC without enough episodes to provide a proper final victory lap season, so they agreed to bring the show back for the fifteenth and last season which began in September of 2008 and concluded on April 2, 2009.
- The entire main cast of the first season also appeared in the fifteenth and final season: Anthony Edwards, Noah Wyle, George Clooney, Eriq La Salle, Sherry Stringfield and Julianna Margulies.
- All original cast members who appeared in season fifteen were listed in the credits with the current stars, not as guest appearances. Alex Kingston and Laura Innes also appeared in the opening credits to the series finale due to their roles in it. In the 2009 episode guest starring George Clooney and Julianna Margulies, Noah Wyle received top billing over both of them.
- By season thirteen, Laura Innes became the longest running cast member of the show.
- Including Gloria Reuben and CCH Pounder (who appeared as recurring guest stars during the first season), the original cast combined for 25 nominations in the Leading and Supporting Acting categories at the Emmy Awards from 1995-2000. Julianna Margulies (Best Supporting Actress, 1995) was the only one to ever win.
- The character portrayed by Leslie Bibb (Erin Harkins) was originally supposed to die in the episode where she and Luka (Goran Visnjic) were in a car accident. The producers changed their mind after the episode had been written and after an ambiguous ending, she resurfaced a couple of episodes later, alive and well.
- Because the original credits were abandoned in season thirteen, neither Maura Tierney or Parminder Nagra were seen with the "Starring" moniker attached to their name, although they were each the lead roles for a time. John Stamos, Angela Bassett and David Lyons were depicted in the opening credits just once when the original style was brought back for the series finale.
- Sherry Stringfield is the only cast member to leave and return to the show. Ming-Na had a recurring role in season one, but came back as a regular in season six.
- The first person to appear on-screen in the first episode is Dr. Mark Greene (Anthony Edwards).
- The first and last episodes of the series are the only two to not air at 10:00 p.m. during the show's fifteen year run.
- Throughout its fifteen-year run, the show had 26 regular cast members, nineteen of whom appeared in the final season at one point or another.