The page is likely to contain spoilers. Readers, beware.
Dr. Harding Hooten
Actor: Alfred Molina
Chief of Staff
- Alliterative Name: Harding Hooten. Alliterative nickname, too: "Hardly Human".
- Catchphrase: Catch characteristics. The way he pours a glass of water just before he starts ripping into someone.
- Hidden Depths: He plays the piano and likes classical music.
- In-Series Nickname: "Hardly Human"
- Jerkass Has a Point: He's hard on the doctors, but he has to keep them in line.
- Jerk with a Heart of Gold: He has a soft side in him, and it's actually not hidden too deep. He fights for his doctors and respects them. His dealing with his ageing mentor is very respectful and kind, or when he had to tragically fire a doctor who made a preventable mistake and killed his patient, he actually tells him that he thinks he's an excellent doctor, but he had no choice. The sacked doctor agrees it's the only way.
Dr. Jorge Villanueva
Actor: Ving Rhames
- Bald, Black Leader Guy: He's the leader among the doctors who look up to him and seek support with him.
- Bald of Awesome: Most definitely. He can pull baldness off and looks awesome.
- Drowning My Sorrows: He goes to a bar regularly when he's feeling down. Sometimes his colleagues join him for a couple of drinks.
- Friend to All Children: He's great with kids and young teens. These patients trust him immediately.
- In-Series Nickname: "El Gato" aka "Big Cat". Everybody in the hospital looks up to him.
Dr. Tyler Wilson
Actor: Jamie Bamber
- The Ace: He's a brilliant and cocky neurosurgeon. However, first episode crushes him and he becomes a downplayed Broken Ace instead.
- Dark and Troubled Past: Implied, when his patient's death triggers a flashback to his brother's death. It's possible this is the reason he became a doctor.
- Heroic BSoD: His young patient — a small boy — dies on him. When it's revealed that he messed up and didn't check all relevant medical history, he breaks down. It has to be a short-lived Heroic Blue Screen of Death, because "Gato" needs him in ER. However, the event haunts him and his Heroic BSOD is on-and-off.
- Hospital Hottie: A Pretty Boy in blue scrubs and white coat. Ladies must be crazy about him — one hot colleague fancies him, and one male patient calls him a baby face.
- Mr. Fanservice: He has one shower scene and sometimes his mornings are shown...
- Perma-Stubble: Rugged manly man, unshaven look is awesome on Dr. Wilson.
- Too Clever by Half: He has all traits of this archetypal character. He's an extremely smart and brilliant neurosurgeon with magical hands. He knows it, and doctor Hooten often calls him on his medical arrogance, especially his failure or reluctance to consult with his colleagues (who are as brilliant as himself). note However, he has sweet bedside manners and he's also very nice to his colleagues, which makes him popular. A Death of a Child patient is the big screw up part of the trope.
Dr. Tina Ridgeway
Actress: Jennifer Finnigan
- My Biological Clock Is Ticking: There are hints that she would like to have family but she's too devoted to her job.
- Heterosexual Life-Partners: She's best friends with Dr. Sydney Napur.
- Hospital Hottie: She's a hot lady doctor.
- Ms. Fanservice: She has a shower scene.
- Your Cheating Heart: Her marriage is a mess, and she cheats on her husband. When she tells her husband, he files for divorce and blames her for destroying their relationship. And he blames Tina's lover even more and sues him.
Dr. Buck Tierney
Actor: Bill Irwin
- Doctor Jerk: His set-up presents him as Dr. Jerk who is an asshole to everyone and only good at his job, but it gets Subverted. He actually cares about lots of things and his boss tells him he's a good man.
- Dude, Where's My Respect?: He thinks people should appreciate his commitment to the transplantation programme. Most of the time things go well and the procedure requires many steps with lots of bureaucratic B.S. He thinks he deserves some respect, and is insulted that people see him as a vulture or predator. He still considers himself an asshole. Conflicted guy, this doctor.
- Character Tic: Dr Buck Tierney has a habit of pulling himself up and down and making a squeaky sound with his shoes.
- Jerk with a Heart of Gold: He shows his jerk side more often though and he seems little too happy to see potential organ donors die, but he's actually a decent person who cares about his patients (he supports one rather crazy patient who wants to eat a kidney...) and has a heart-to-heart with his boss who says he knows he's a good person.
Dr. Sung Park
Actor: Keong Sim
- Asian Rudeness: He's extremely blunt and sometimes rude to his patients, and similarly to his colleagues.
- Asian Speekee Engrish: His English is broken and fits the description, but other than that, he's nothing like this stereotype and counts as a subversion. He's an extremely self-assured and brilliant neurosurgeon with blunt-to-rude bedside manners.
- Beneath the Mask: He has terrible bedside manners in general. He felt genuinely sorry for letting a widow to decide whether to pull a plug. He went to apologize and cried. In the rain.
- Brutal Honesty: He has no problems telling people what their problem is. "Too fat."
- Catchphrase: "No do — dead" and variations. Super cool way of telling his patients that he really recommends the procedure.
- Hidden Depths: He has a perfect pitch and plays the violin very well. He loves music very much. Surprisingly, he can also recognise a brilliant literary mind by reading a couple of pages. Considering his English language skills, that's impressive. Despite the abovementioned terrible bedside manner, he's incredibly compassionate and reassuring with Wilson after Tina's surgery.
- You No Take Candle: He-speak-broken-English. Interestingly, his wife is shown speaking English at home, and she has a clear, normal accent. One has to wonder where his language skills come from.
Dr. Sydney Napur
Actress: Sarayu Rao
Attending cardiothoracic surgeon
- Brutal Honesty: She cannot take bullshit from either patients or her colleagues. She's not afraid to speak her mind and sometimes can be a bit controversial.
- Heterosexual Life-Partners: With Tina. She calls Tina her best friend several times.
- Married to the Job: People say it to her very often. Variations include asking her if she ever stops obsessing about her job and stuff. She doesn't.
- My Biological Clock Is Ticking: It's a source of angst for her that she doesn't have children, but she's too committed to her job. Gato also thinks it will happen when she meets the right guy.
- Office Romance: She and Dr. Lieberman are not from the same department, and the hospital doesn't seem to have a policy against doctors dating each other.
- Pitbull Dates Puppy: Dr. Napur is very tough and Dr. Lieberman is a little scared of her. When El Gato suggests that they might not get on, she gets angry.
Dr. Michelle Robidaux
Actress: Emily Swallow
- Brainy Brunette: Michelle has long straight hair. She's a pretty and clever woman.
- Hospital Hottie: Michelle gets hit on by patients and is referred to as "the pretty brunette".
- The Intern: She's a resident and the youngest and least experienced on the team. Still very capable and a competent doctor.
- UST: Has one tense scene with Dr. Delany, a one-shot character. Lots of touches. The tension is not resolved with a kiss or sex, though.
Dr. John Lieberman
Actor: Jonathan Silverman
- Adorkable: Tina and Sydney discuss whether he's attractive or dorky. They settle on "dorky enough".
- Love Interest: He asks Dr Napur out in the first episode. She kind of made him. Their relationship lasts with the inevitable ups and downs.
- Office Romance: He dates her colleague.
- Pitbull Dates Puppy: He's the puppy. Dr. Napur is way tougher than he is.