ER wiki

Nurse Carol Hathaway is a fictional nurse from the television series ER, She is portrayed by Julianna Margulies.


Early life

Carol grew up on the West Side of Chicago. Her father died when she was barely old enough to remember him. She says in season four that he, like Carol, suffered from depression, and it is hinted that this may have contributed to his death. Carol's mother used to tell her that "it was an accident," which Carol finds suspicious.

Actress Julianna Margulies has said that, when playing Carol, she developed a backstory in her mind that her father's death is the reason that Carol became a nurse.

Carol has mentioned that she is the youngest child in her family (as she told Dr. Anna Del Amico that she is the youngest of two sisters, but we never meet them on the show).

In the season two episode, "Home," the high school shown on Carol's yearbook is St. Scholastica High School. In season three, however, she mentions that she attended a school called St. Monica. In a season 3 episode, her chemistry teacher remembers her as a promising student. She attended the same high school as Dr. Maggie Doyle, who is two years younger. In season 3, Carol states that she graduated high school in 1985; combined with the fact that she completed a nursing master's degree, this means that she ascended to the position of nurse manager at a major emergency room by age 27 after just three years of full-time work experience.

According to Carol’s mother, she tried the flute, cheerleading, ballet, and business school all at various times, but quit each thing, fearing that she wasn’t good enough. She did, however, finish nursing school with a Master’s degree. When she considers medical school, she begins taking pre-med classes at Malcom X Community College.

In season 1, while caring for an abandoned Russian child with AIDS, it is revealed that Carol is half-Russian and able to speak the Russian language to a certain extent. She says that her mother tried to teach her Russian, but she didn't cooperate with it. Carol's heritage arises at other points throughout the series, as well, particularly during the holidays, when she is shown wearing a traditional Ukrainian Christmas dress.

Career Overview

Carol Hathaway is a registered nurse and is the nurse manager in the emergency room of Chicago's County General Hospital. In season two, it is revealed that she has a master's degree in nursing when she completes a performance evaluation for physician assistant Jeanie. Throughout the series, Carol is referred to as both the nurse manager and the charge nurse/head nurse.

Carol is portrayed as a highly qualified trauma nurse. In the eighth episode of season one, she says that she is certified to perform forensic exams, and in season two, she rides along with paramedics in order to renew her MICN (mobile intensive care nurse) certification.


Carol is tough and assertive. She can be seen attending hospital meetings and fighting for her nurses. She is sensitive towards the lack of recognition the ER nurses experience.

In the pilot episode, Dr. Mark Greene refers to her as "very popular" with the staff in the emergency department.  She takes her role in the ER seriously and, in one episode, is said by Dr. Weaver to be “the best nurse” they have on staff at County General. However, she doesn’t like to take orders and is sometimes hostile to the physician assistants, as well as the interns. She once told surgeon Peter Benton in the first season,

"Haleh may not be able to cross clamp an aorta, but she has over 20 years experience in emergency medicine and if you would step off your pedestal maybe you would realize it's the nurses that make this place run and not you."

Carol’s high level of skill and knowledge mean that she is often teaching the med students and interns how to start IVs, perform blood gasses, or do pelvic exams. However, she often feels like her abilities — and the abilities of the other nurses — go unappreciated, leading her to appear insecure and even jealous at times.

When physician assistant Jeanie first arrives, for instance, she and Carol don't get along, as Carol feels that physician assistants are encroaching on the territory of the nurses. However, the two eventually become friends.

Carol tells Doug that she hates to take orders from interns, and this is one of the things that leads her to consider medical school. “You’re a very competitive person,” he tells her in season three. As the seasons progress, Carol becomes less insecure and less competitive toward the med students, although she is initially shocked when she learns that Abby is a medical student.

Carol Hathaway is considered to be a complicated character. Julianna Margulies told The Los Angeles Times in 1994, "[Hathaway] is strong and controlling and that’s why she’s good at her job. She has a dry sense of humor and a very dark side to her that she doesn’t wear on her sleeve. She’s very compassionate, even if she’s dealing with her own demons."

Mental health

Carol’s mental health is an important part of the arc and backstory for her character.

Shortly after her character is introduced on the show, she is rushed into the hospital after an overdose of barbiturates in a failed suicide attempt on St. Patrick’s Day, 1994. She had been working on shift just hours prior, making jokes and seeming like herself.

However, there are some moments of foreshadowing. As Carol leaves her shift at the end of the day, various staff members tell her, “See you tomorrow,” to which Carol only responds with, “Goodnight.”

When the paramedics bring her in hours later, the ER staff is stunned and almost too shocked to work. Dr. Greene has to continually remind them to treat her like any other patient. After they are finished working on her, Dr. Lewis mentions that "even her fiance didn't know about it" indicating Carol hadn't shared her suicide plans with anyone.

Earlier in the episode, the fiance in question is referred to by Dr. Benton as an orthopedic physician, implying that this is Dr. John Taglieri. At the time, Carol was also living with a roommate, who is shown during the pilot, but never referenced again. The roommate tells Dr. Greene that Hathaway combined a scotch with the pills.

Carol’s suicide attempt is serious, with the staff at times speaking of her in the past tense, as they don’t expect her to survive. Dr. Greene intubates her and Dr. Lewis repeats her lab test several times, clearly upset to see that her barbiturate level (serum barb) has stayed in a potentially fatal range.

Carol is close friends with both Dr. Lewis and Dr. Greene, and the two order aggressive medical care, which results in her miraculously surviving after being comatose.

The next time Carol is seen is when Doug goes to visit her around eight weeks later; Carol’s mother has temporarily moved in with her to help her recover.

Although she later denies it, the staff suspects that her suicide attempt was brought about by her failed romance with Doug, a womanizing pediatrician also working in the ER. Before she dated Tag, Carol and Doug had dated for two years.

Later in the series, when Doug and Carol begin dating again, Carol's mother is worried and reminds Carol that she was there to take care of her the last time that Doug broke her heart.

However, Carol explains in the show's third episode, "Going Home", that the attempt was actually caused by “too much stuff piling up” and feeling trapped. In "Sharp Relief", she tells paramedic Greg, "I thought of everybody but me when I tried to kill myself. I just got wrapped up in everybody else's expectations of me and forgot who I was."

In a 2021 interview on The Skimm podcast, Julianna Margulies recalled her character's first episode. She said, "Whenever my character was at the medicine cabinet getting meds for her patients, she was putting some in her pocket for herself [for her eventual suicide attempt]. Not that they ever paid attention to that. If you re-watch the pilot, you can probably see her pocketing some medication."

Carol returns to work not long after Doug visits her, eight weeks after her suicide attempt. As she prepares for the day, she is clearly anxious and unsure. Get-well-soon greeting cards can be seen on the mantle and shelf in her bedroom as she lays out her nursing uniform. When she arrives at work, she is haunted by images of herself being brought into the ER on a gurney. She tries to make jokes to lighten the mood of her arrival.

She tells Dr. Greene that her therapist suggested she consider working in a doctor's office instead of the high stress environment of the ER, but she couldn't imagine doing that. She wonders if she's returned to work too quickly, but expertly runs a trauma with Dr. Greene that boosts her confidence. She also meets a patient who reminds her that life is a gift, which she vows to take to heart herself.

In a 1996 interview with US Magazine, Margulies expressed her disappointment that the show didn't dive deeper into Carol's mental health struggles. She said, "[Executive Producer] John Wells says Hathaway’s ratings go up when she’s lighter, and I know they think the show is dark enough. But I think they missed the boat."

Instead, the reasons for Carol's suicide attempt are sprinkled throughout the series. She often uses her experience to connect with others.

After Jeanie's HIV status is revealed to the staff, Carol privately tells her that she once tried to kill herself, so she knows what it's like to come back to work and have everyone treat you differently. The two were once competitive rivals, but now, she suggests they be friends. Jeanie ends up working in Carol's free ER clinic.

In many other episodes, Carol tells her patients and colleagues, when they are in distress, that they "have to deal with" their feelings and that "keeping things inside makes things worse."

In the season one episode "ER Confidential", Carol talks with a young patient about the importance of not keeping secrets from others, because it destroys you inside. She tells him that she’s hurt the people she cares about with her own secrets. Afterward, she tells her fiancé, Tag, that she cheated on him with Doug before her suicide attempt.

In the episode, "Long Day's Journey", Carol helps work to save a woman who does die by suicide in the ER. After the experience, Haleh tells Carol that she knows that must have been hard for her to relive. Haleh asks if Carol wrote a suicide note like the woman they had worked on. Carol replies, “No. I didn’t know what to say.”

In "The Secret Sharer", Carol cares for another patient who has attempted suicide. While working on the girl, she comments to Mark that she “hates this” and is clearly affected by the patient, to whom she later shares the story of her own attempt a year before.

After caring for the patient, Shep comments - unaware of Carol’s history - that anyone who takes a bunch of pills just wants attention and doesn’t really mean it. Annoyed, Carol replies, “I really meant it,” shocking him and leading him to try to apologize to her several times. Later, he tells her that he is glad that her suicide attempt failed. Carol answers, “Me too.”

In "Into That Good Night", Mark and some of the other staff become emotional while caring for a patient who is dying of heart failure. Affected and watching from outside of the trauma room window, Carol asks Mark to please not remind her that she should be grateful to be alive.

In "Night Shift", she tells Doug that she "didn't think much of herself" when they dated before her suicide attempt, but now she "feels good." She explained, "I used to think I couldn't do things. Now, I'm taking a pre-med course. I guess it's about being in control."

In "The Long Way Around", when Carol is held hostage during a robbery at her local convenience store, she ends up telling one of the robbers that she used to imagine herself doing more with her life. After Carol returns to work, many of the staff members express concern for her, repeatedly asking if she is okay after her experience. In another season three episode, "Faith", she expresses resentment toward her mother and tells her that she never felt supported growing up.

In season six, after the birth of her twins, Carol appears to struggle with postpartum emotions. On her first day back to work after having her daughters, Elizabeth finds her crying in the lounge. Carol tells her that she always cries at home, and then feels better afterward. Later in season six, she tells Kerry that she "hates" her life, overwhelmed and stressed from raising twins by herself.

Season 1

Carol's recovery from her suicide attempt and her work to rebuild her life is a major part of season one.

She and orthopedic surgeon Dr. John "Tag" Taglieri (Rick Rossovich) plan their wedding, despite Carol seeming to have misgivings. At one point, she tells Tag that she wants to make sure that she's ready after all that has happened.

Carol dated Doug Ross for two years before her suicide attempt. During her first day back to work, it becomes obvious that while she is still attracted to Doug, she harbours some animosity towards him. She recognizes that Doug feels guilty about her suicide attempt and tells him, "there were actually more depressing events going on in my life than you."

Meanwhile, Doug continues to try to win Carol back, and although their friendship is slightly rekindled, Carol keeps Doug at a distance in both professional and private matters.

Later in season one, Carol attempts to foster adopt an abandoned Russian girl named Tatiana, who is suffering from AIDS and was left in the ER. Tag isn't supportive and doesn't want to go through with the adoption. Carol passes the home visit, but a background check showing her attempted suicide only months earlier causes her application to be denied.

Carol is devastated at being denied the chance to foster Tatiana. She looks to Doug for comfort. Carol shares with him that she feels defective for being unable to adopt Tatiana. She says that she has worked hard in therapy, and has been in therapy for nine months at that point.

In "ER Confidential", after giving advice to a patient to be more honest, Carol tells Tag that she cheated on him with Doug before her suicide attempt and recently kissed him. Tag becomes angry and tells Carol that he has been patient, but her suicide attempt can’t be an excuse for all of her behaviors. However, in the next episode, Carol is wearing an expensive engagement ring from Tag.

In the season finale, on the day of Carol and Tag's wedding, Tag tells Carol that he knows she could never love him the way that he loves her. Carol finally admits that this is true. He decides that he can't go through with the wedding. However, the guests still hold the reception.

Carol wonders to Doug why she can't be with a guy "who is good and decent" and loves her. She tells him, "I just want to be happy and I'm so afraid I never will be." Doug assures her that she will.

The rest of the ER staff attempts to cheer her up and help her feel better at the wedding reception, with food, drinks, and music. Carol makes a speech thanking them and acknowledging her gratitude at being alive at all.

Season 2

Carol begins season two by purchasing a run-down, rickety house. As the seasons progress, the house slowly transforms into a vibrant living space, mirroring Carol's work to rebuild her life.

Carol reluctantly starts a new relationship with a paramedic named Ray "Shep" Shepard, but he eventually moves in with her. Shep and Carol seem to have a fun relationship, with Shep assisting with her home repairs, but he sometimes clashes with Carol's co-workers over his judgmental personality, putting her in the awkward position of having to mediate.

Then, Shep's work partner, Raul Melendez, dies in a fire trying to rescue children from a burning building. Shep's partner was badly burned and later dies in the ICU. Shep becomes aggressive and even violent toward others in response to his anger at Raul's death. At one point, he's even almost violent toward Carol.

Thinking that she can help him change, Carol attempts to cover for him during an investigation into a violent outburst where Shep injured someone while he was working. Carol ends up regretting that she covered for him.

Despite Carol's attempts to get him professional help, Shep refuses. Carol tells him that she finally has her life together and doesn't feel like she can be with him if he isn't in therapy. Although Carol loves Shep, she decides that she can't watch him self-destruct and ends their relationship.

In the season finale, Carol quits the ER in disgust at the hospital's insurance practices, but she later returns without explanation. The next time she's upset, Haleh simply jokes to her, "you could always quit again."

Season 3

In season three, Carol goes through financial problems. She takes out a second mortgage and her car is repossessed because she's three payments behind. She wants to sell her house, but the real estate agent tells her that no one will buy it.

Things get even worse when a labor dispute arises concerning the re-assignment of her nurses. As nurse manager for the ER, Carol is privy to management decisions and she finds herself torn between her friends and the hospital administration.

During a nurse sickout, while she is busy telling the substitute nurses where to find supplies and explaining how to use the equipment during a trauma, she forgets to check the label of the blood being given to the patient. After the trauma, when she is cleaning up and taking inventory with Dr. Weaver, she realizes that she accidentally transfused the wrong blood into the patient.

Although it is unclear whether it was the blood or his other injuries that caused his death, Carol blames herself. She visits the grave of the patient with flowers.

The administration initially does not punish Carol for this incident and uses it to cast the sickout in a bad light, but she resents the administration's actions and believes she is not being punished sufficiently for her error. She talks to the press and gets suspended.

During her suspension, Carol is held hostage at gun point during an armed robbery at her local grocery store. She treats several injured people and performs advanced procedures, including a tracheotomy and a chest tube, using only the supplies in the store. She manages to escape the incident, shaken but unharmed. Shortly after this experience, she is released from her suspension.

Carol is shown taking pre-med classes at a local college, and later takes the MCAT with Doug's encouragement. She assumes that she failed when in fact she did very well. She scores in the 85th percentile, impressing the hospital and leading Kerry to take her under her wing.

Kerry teaches Carol to intubate a patient, which she does expertly. However, by the end of the day, Carol decides against becoming a doctor after realizing that her job as a nurse is worthwhile. She tells Doug that she only took the test to prove she was capable.

During the last few episodes of the season, Carol and Doug become closer and eventually rekindle their relationship. Still, their relationship is held up by Carol's insecurities.

Season 4

Professionally, Carol starts a free clinic in the ER with the help of Carter's grandmother's foundation. She staffs the clinic by hiring a nurse practitioner, Lynette. She also uses volunteers from the ER staff, particularly Jeanie, with whom she has now become friends (the two were previously rivals) and it is extremely successful.

Personally, Doug and Carol's relationship starts to get more serious. Doug later proposes to Carol in front of the ER staff, which she hesitantly accepts. Doug notes that she "is waiting for the other shoe to drop."

She explains that she's already done the wedding thing and just wants to take things slow. Still, Doug plans a secret wedding for the two of them. The same day of his planned wedding, Carol has a conversation with paramedic Greg Powell. He tells her about his mother's suicide and she opens up about her own attempt. They end up kissing.

Afterwards, Carol takes a long walk alone "to think." When she arrives home, she tells Doug about what happened. He becomes angry and leaves. Later, when the two are working at the hospital, they have a heated conversation where Carol asks Doug for time and space. He forgives her for kissing Greg and tells her that he'll wait until Carol is ready to get married.

Near the end of the season, Doug gets Carol involved in a case where he uses ultra-rapid detox on a drug-addicted baby without the mother's permission which gets Doug in hot water.

Season 5

Carol and Doug's relationship is still strong and, after a pregnancy scare, they decide to actually try for a baby together.

Toward the middle of the season, Carol gives Doug a PCA machine from her clinic to help Ricky Abbott, an 8-year-old terminally ill boy with ALS, and his mother, Joi. After Doug gives Joi the code to Ricky's PCA machine, the mother uses it to deliver a fatal dose of dilaudid to Ricky and causes his death.

Doug's career at County is put into jeopardy. His choice also impacts Carol, who is forced to step down from overseeing her clinic, and Mark, who wasn't aware of the situation.

To avoid having her clinic closed, Carol asks Lynette, the nurse practitioner who she had hired for the clinic, to take over for her. While they mostly got along, Lynette and Carol had clashed at times, with them each holding different views on how to manage difficult patients.

For example, in one episode, Lynette wants to restrain a patient by using sedatives, which Carol feels is unethical. They also have different views on how best to serve at-risk populations, but Lynette ultimately agrees to take control in order to keep Carol’s clinic open.

After the incident, Carol says that she is allowed to keep her job in the ER, but that she is out of management. However, in season six, she can still be seen completing managerial tasks, such as signing time cards for the nurses.

Doug later decides to leave Chicago for a job in Seattle. He asks Carol to come with him, but Carol turns him down. She explains that Chicago is her hometown, with her job, family, and friends all in the city. She wants him to stay for her, and emotionally tells him she doesn't want to wake up without him. However, Doug ends up leaving Chicago alone.

After Doug has left, Carol begins experiencing headaches and insomnia that she at first blames on stress. She soon realizes that she is actually pregnant. She struggles with the emotions of being pregnant without Doug, even though she tells him not to return to Chicago when she informs him of her pregnancy. She doesn’t want him to come back only because she is pregnant.

Unsure of her complicated feelings, she tells Mark that she was “very clear and strong” when telling him not to come back — even though she still believed he’d come back.

Carol also struggles with the risks of being pregnant while working as a trauma nurse. She is kicked in the stomach by a child, faced with the need to care for a woman who has an infection that is dangerous to pregnant women, and accidentally exposed to an x-ray. Physically, she is often exhausted and has fainting spells. She tells Elizabeth that she is suffering from morning sickness and fatigue. She confides in her that she doesn't want to be a single mother.

Later, when an OB appointment is suddenly cancelled, Carol tries to perform an ultrasound on herself. Mark and Elizabeth catch her and offer to help. They all learn that she is actually having twins.

Season 6/Departure

By the beginning of this season, Carol is now heavily pregnant. She also starts a good friendship with newcomer Dr. Luka Kovač.

On Thanksgiving Day, Carol goes into labor on the El. She manages to get off at the next stop. Luckily, Luka sees Carol there having contractions and helps get her to the hospital. Halfway there, Carol loses consciousness and Luka carries Carol to the hospital.

Concerned about her vitals and the fact that she passed out, Dr. Weaver wants to examine Carol in the ER before sending her up to OB. It turns out that Carol is too close to delivery and will have to give birth to her first twin in the ER, despite her protests.

She gives birth to twin daughter, Tess, before being taken to OB. Dr. Mark Greene arrives and is by her side. Her nurse is Abby Lockhart, who she will eventually end up working with in the ER.

When Carol goes into labor again, there are problems that cause her to have a c-section. Carol delivers her second twin daughter, Kate (named after Mark's mother's middle name), but she suffers dangerous bleeding complications from the c-section, which Carol later recovers from.

After the birth of the twins, Carol struggles to balance child-rearing, her postpartum emotions, and her return to work. She also tells Mark that she knows the girls deserve a father. Mark then says that Doug has been seeing them, implying plane visits from Doug off-screen.

Carol tells Luka that her daughters' last names are Ross, not Hathaway. Carol and Luka appear to start a relationship with each other, but Carol is still focused on Doug and seems to send him mixed signals. At one point, Luka hints to Carol that she has to let the past go.

Meanwhile, Doug still wants Carol and their daughters to come live with him in Seattle. Carol cannot decide whether it's the right thing to do, telling Luka that her pride kept her from going with him. "I wanted him to stay for me," she said. "I thought I should be at least that important to him."

However, in season six, episode twenty-one, Carol treats a woman with a do-not-resuscitate order who is dying of end-stage ovarian cancer. She resuscitates her in order to help her husband and daughters say goodbye, despite the choice going against Dr. Weaver's demands.

Carol is moved by the family and has an epiphany. She decides to reunite her own family and abruptly leaves work, telling Mark to tell Kerry that she won't be in the next day. She says that she'll call him from the plane.

She stops to tell Luka how sorry she is and that she is still in love with Doug. She tells him that she's been in love with Doug since she was 23-years-old and that he is her soul mate. She tells him that he'll find someone, too.

Carol flies out to Seattle that day to reunite with Doug and move there. It is later revealed that Carol sends for her daughters, who she left with her mother in Chicago, the next day.

After departure

When Susan Lewis returns to the ER in season 8, she asks about Carol. The nurses tell her that she got on a plane, sent for the twins, and they haven’t seen her since.

In the episode "Dead Again", Elizabeth Corday is grieving the death of her husband, Mark Greene. She becomes emotional when she enters the doctor’s lounge and sees a photograph of him smiling with some of the hospital staff before his death. Carol is in the photograph.

In the season 11 episode "The Show Must Go On", Carol’s voice telling him to hurry up is one of the voices that Carter hears in his head as he leaves the hospital.

In the Season 14 episode "Status Quo", Jeanie Boulet mentions Doug and Carol when she returns to the ER. Nurse Haleh Adams says that Doug recently sent her a photo of the twins. She says that they are still loving Seattle and that their twin daughters are now in third grade. Jeanie says that she keeps meaning to visit.

At the end of the Season 15 episode "The Book of Abby", long-serving nurse Haleh Adams shows the departing Dr. Abby Lockhart a closet wall where all the past doctors and employees have put their locker name tags. Amongst them, the tag "Hathaway" can be seen. The same happens again during "Shifting Equilibrium", when Dr. Neela Rasgotra puts her own name tag on the wall.

Carol Hathaway appears again in Season 15. She and Doug are now married and practice at the University of Washington Medical Center, where Carol is a transplant coordinator. During the episode, Carol and Doug help a grieving grandmother (Susan Sarandon) donate her grandson's organs.

One of the organs, a kidney, is given to "some doctor", unbeknownst to both Doug and Carol that it is their former co-worker and friend, John Carter. While on the job she met the two current employees at Cook County General Hospital, Neela Rasgotra & Sam Taggart.

While it isn't expressly stated that the two are married, there are wedding rings on both of their hands. However, Carol introduces herself to the staff in the hospital lounge as “Carol Hathaway,” not Ross.

Doug and Carol also briefly discuss their now school age twin girls, who Carol says spent the morning complaining about a spelling test.



Doug Ross

Carol and Doug are ex-lovers in the first season of ER. While the two obviously harbour interest in each other, Carol seeks to move forward with John Taglieri. Doug continues his womanizing habits. After an incident where one of Doug's lovers dies, he realizes he needs to change the way he lives. The two get closer once more, but separate when Doug resigns from the hospital and moves to Seattle. Carol does not tell him about their twin girls until after the first trimester of her pregnancy, when she sends him a faxed letter. He calls to discuss returning to Chicago, but she tells him not to come, not wanting the pregnancy to be the only reason he returns. She gives their daughters his last name.

In "Such Sweet Sorrow", Carol realizes she is still in love with Doug, and catches a flight to Seattle. The two are implied to have married in season 15.

John "Tag" Taglieri

Carol and Tag almost wed in the first season, but mutually step out of the marriage the day of the wedding.

Ray "Shep" Shepard

Following a paramedic ride-along with Shep and his partner Raul, Carol starts a relationship with Shep. The relationship turns sour when Raul dies from burns sustained from a fire Shep insisted the two head into. Carol, disturbed by the violent change in Shep's behaviour, cuts off their relationship.

Luka Kovač

Carol is immediately interested in Luka when he enters the ER as a moonlighter. Carol and Luka remain platonic for most of their time together, but share a tentative kiss on the day he helps her purchase a used car.

Their budding relationship is shadowed by the memory of Doug, who sends her a box of animal crackers (a memento from their past relationship) on her birthday. After a moving interaction with the family of a woman dying of end-stage ovarian cancer, Carol realizes she is still in love with Doug and wishes to live with him in Seattle. She promises Luka he'll find someone, and then leaves the hospital to be with Doug.


Mark Greene

Carol and Dr. Mark Greene are shown to have a close friendship throughout Carol’s time in the ER. Carol often confides in Mark, especially during her pregnancy. When Carol delivers her twins, Mark is her Lamaze coach and advocates for her during an emergency C-section.

Susan Lewis

Carol is good friends with Dr. Susan Lewis. Carol asks Susan to be her maid-of-honor in her wedding to Taglieri. When Carol attempts suicide in the show’s pilot episode, Susan rushes her blood test to the lab herself and repeats the test multiple times when she learns that her barbiturate level is in a potentially fatal range. Later, she is visibly upset as she tends to Carol, asking Nurse Lydia if her barbiturate level has gone down at all. Throughout the show, Carol is always complimentary toward Susan’s skills as a doctor, at one point telling Dr. Doyle that Susan “was always this good.” In one episode, Carol and Susan relax in beach chairs on the roof of the hospital to de-stress during their shifts.

Elizabeth Corday

While she initially worries that Dr. Elizabeth Corday might be interested in Doug, Carol and Elizabeth still become fast friends. In one episode, the two agree to get drinks together after work. In another episode, they are seen having drinks and conversation at Elizabeth’s apartment, along with Dr. Del Amico. Elizabeth is the first person who Carol tells about her pregnancy. She also confides in Elizabeth about her fear of being a single mother.


  • Actress Julianna Margulies said in a 2012 Times Talk interview that she spent six years playing Carol as an only child and was blindsided to see her written as having sisters. She told the interviewer, Bill Carter, "I had actually done research on being an only child."
  • Carol (like Margulies) is left-handed.
  • In season two, Carol explains to an impressed Mark that she has a natural aptitude for simple math when she’s able to quickly perform calculations in her head during a trauma.
  • In the season one episode, "Going Home", Carol's name badge has the spelling of her name as "Carole." In later episodes, her name is spelled "Carol" on the badge. In another episode, Ghosts, Carol attends her physics class still wearing her nursing uniform, but with a name tag that says “McKenzie Rain, M.D, Psychology.” This is presumably because the episode is set on Halloween.

ER Characters
Characters Mark GreeneDoug RossSusan LewisJohn CarterCarol HathawayPeter BentonJeanie BouletKerry WeaverAnna Del AmicoElizabeth CordayLucy KnightLuka KovačAbby LockhartCleo FinchDave MalucciJing-Mei ChenMichael GallantGreg PrattNeela RasgotraSamantha TaggartRay BarnettArchie MorrisTony GatesSimon BrennerCate Banfield