第 15 季 共 22 集
播出时间：2008年9月26日
第 1 集 Life After Death
播出时间：2008年9月26日
Abby awakens after the ambulance explosion and rushes to check on Pratt; Sam and Gates rush to the scene; Morris and Neela struggle to keep up with Pratt's injuries.
第 2 集 Another Thursday at County
播出时间：2008年10月10日
Everyone in the ER is trying to cope with the loss of their colleague. The staff feels defensive toward the new Chief and her tough disposition. Gates and the new interns treat a bio terrorist, who has a lethal secret that endangers them all. Neela makes a great effort to get Dubenko back on the surgery staff, and gets help from an unexpected souce.
第 3 集 The Book of Abby
播出时间：2008年10月17日
Neela is upset when she finds out Abby's good news second hand; the new chief, Catherine Banfield, and Abby disagree on how to treat a gunshot wound victim; Abby defends Sam when she goes before a nurses disciplinary board.
第 4 集 Parental Guidance
播出时间：2008年10月24日
Banfield is caught off guard when a man tries to steal her wallet; Dr. Dubenko returns to the surgery team; a family member is suspected of hurting a young gymnast; Sarah gets her tongue pierced.
第 5 集 Haunted
播出时间：2008年10月31日
Sam's time is taken up by her studies for a pharmacology exam, leaving Gates feeling neglected. A school fight results in a stabbing, with Brenner treating the victim and trying to uncover the truth behind the story. Morris has a surprise for Neela. Gates gets locked in a stairwell with a quiet young boy on Halloween night.
第 6 集 Oh, Brother
播出时间：2008年11月7日
Dr. Banfield is irritated when Morris takes Chaz under his wing and teaches him risky medical procedures; Neela is unhappy when Dr. Banfield undermines her authority with an intern.
第 7 集 Heal Thyself
播出时间：2008年11月14日
Dr. Banfield takes a run to clear her head but finds herself trying to rescue a three-year-old girl from drowning in a nearby lake. Gates tries to pull some strings in the ER to help his homeless war hero. Banfield is reminded of her own experience at County with Dr. Greene caring for her son as she tries to save the young three-year-old girl from certain death. Meanwhile, the interns continue to struggle to keep up in the ER.
第 8 集 Age of Innocence
播出时间：2008年11月21日
Sam gets frustrated with Gates when he gets obsessed with finding a homeless war hero. Neela is upset at her intern after he gets the entire surgery department into a lawsuit. A husband and wife come into the ER after someone tried to burn down their home. Brenner loses his cool with a patient and it gets physical.
第 9 集 Let it Snow
播出时间：2008年12月5日
Banfield and Morris go to the coffee shop at 3 a.m. and are served by 20-year-old Debbie who is six-months pregnant. The doctors treat someone with a heart problem and Alex. Chaz must look for a missing 7-year-old boy who saw his sister die.
第 10 集 The High Holiday
播出时间：2008年12月12日
Morris' father arrives at the ER's doorstep and leaves him an unwanted package. Sam wants Alex to get off the ventilator as quick as possible following his accident. Meanwhile, a woman is in danger of being deported despite her high-risk pregnancy.
第 11 集 Separation Anxiety
播出时间：2009年1月9日
Alex is set to be released from the hospital. Doctors treat African-American brothers Curtis Bennet, 17, who has abdominal pain and 10-year-old Quincy Bennet who has a knee injury. Both were injured during a drug deal that went terribly wrong. There's still some residual tension between Gates and Sam. A female patient in police custody doesn't want to be examed by Morris. A 13-year-old patient named Anastasia messes with Neela's love life.
第 12 集 Dream Runner
播出时间：2009年1月16日
Neela has a recurring dream; Gates tries to save a patient who jumped out of a window while sleeping; Neela is surprised to see Dr. Corday.
第 13 集 Love is a Battlefield
播出时间：2009年1月23日
Morris tries to help a girl who was hit while riding her bike; Gates can't get over his feelings for Sam; Neela is flustered when Dr. Brenner returns from Australia.
第 14 集 A Long, Strange Trip
播出时间：2009年2月6日
Morris and Gates treat an older man who was assaulted on the street; Sam gets a surprise visit from her sister; Dr. Morgenstern visits County General when he discovers an old mentor is ill.
第 15 集 The Family Man
播出时间：2009年2月13日
A mother is severely injured by a car accident in the ambulance bay; an insurance company frustrates Morris; Neela tells Brenner about her offer in North Carolina.
第 16 集 The Beginning of the End
播出时间：2009年2月20日
It's Valentine's Day. Dr. John Carter is back at the County. Brenner and Neela are getting closer. Dr. Banfield is having a hard time trying to have a baby. And Puck and mushrooms may not be a good combination.
第 17 集 T-Minus-6
播出时间：2009年2月27日
Carter finds himself struggling with County's new technology and procedures. After becoming frustrated with the in vitro-fertilization, Banfield and her husband discuss adoption as an option. Sam's mother arrives in an altered state of mind.
第 18 集 What We Do
播出时间：2009年3月6日
A camera crew interviews the staff at County General for a documentary on emergency medicine. Morris’ cop girlfriend gets injured on the job and is rushed into the ER with gunshot wounds. Neela wonders why her relationship with Brenner lacks so much communication. Sam struggles to make amends with her mother.
第 19 集 Old Times
播出时间：2009年3月13日
Neela and Sam are shocked when they arrive back to the airport with transplant organs only to find that their plane has left them. Dr. Carter gets a surprise visit from an old friend while waiting for his kidney transplant. Dr. Banfield bonds with an abandoned baby boy that is left at the ER.
第 20 集 Shifting Equilibrium
播出时间：2009年3月20日
On Neela's last day at County, she has doubts as to whether she is making the right decision.
第 21 集 I Feel Good
播出时间：2009年3月27日
The ER doctors and nurses help out at Camp Del Corazon, a camp for kids who have had open-heart surgery, working alongside the camp counselor (guest star TOM ARNOLD).
第 22 集 And in the End...
播出时间：2009年4月3日
As Carter prepares to open a new facility for the underprivileged, some old friends/colleagues gather. Rachel Greene, Mark Greene's daughter, applies for an internship at County.
