Family
-Chole Lewis (Susan's Sister, Series 1 and 2) - Kathleen Wilhoite
-Cookie Lewis (Susan and Chloe's Mum) - Valerie Perrine
-Henry Lewis (Susan and Chloe's Dad) - Paul Dooley
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-Jennifer Greene (Dr Greene's Wife, a Lawyer, later divorced. Series 1+) - Christine Harnos
-Rachel Greene (Dr Greene's Daughter, Series 1+) - Yvonne Zima
-Craig Simon (Jenn has an afair with and later marries)- Bruce Nozick
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-Mae Benton (Dr Benton's Mother) - Beah Richards
-Jackie (Benton's Sister) - Khandi Alexander
-Walt (Benton's Brother in Law) - Ving Rhames
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-Carla Rhys (Bentons Girlfriend and Sons Mother, Series 3+) - Lisa Nicole Carson
-Rhys Benton (Benton and Carlas Baby Son, Series 3+)
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-Helen Hathaway (Carols Mum) - Giorgi Tarlian or Rose Gregorio
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-Al Boulet (Jeanies Husband) - Wolfgang Bodison (1st Series Only), Michael Beach
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-Ray Ross (Doug's Dad, dies in a car crash) - James Farentino
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-Chase Carter (Carters cousin, has a heroin problem. Overdoses leading to brain damage) -
    Jonathan Scarfe
-Millicent Carter (Carters very rich Gran) - Frances Sternhagen
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-Scott Anspaugh (Donald Anspaugh's Son. Has B Cell Lymphoma, Dies.) - Trevor Morgan

Recurring Patients and Families
-Ivan (Liquor store owner, keeps getting shot during robberies) - John LaMotta
-Mrs Cavanaugh/Madam X (Sings her way around the ER) - Rosemary Clooney (George's
    Aunt)
-Patrick (Big loveable simpleton) - Kevin Michael Richardson
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-Loretta Sweet (Ex Prostitute, now a Secretary, has Cervical Cancer) - Mary Mara
-Jimmy Sweet (Loretta's Son) - Jake Lloyd
-Annie Sweet (Loretta's Daughter) - Ashlee Lauren
-Sean O'Brien (Suing the Hospital/Mark after his brother died when, as an innocent
    bystander, he got caught up in a drug deal that went wrong) - Bradly Whitford
-Allison Beaumont (Comes into the ER following a car crash, Corday fights to save her leg.
    Appears later as a trainee paramedic. Injured again, Corday fights to save her.) - Michele Morgan

Other recurring characters
-Linda Farrell (Pharmaceutical Rep and one of Doug's Girlfriends) - Andrea Parker
-Hulda (Flight Attendant and one of Doug's Girlfriends) - Nicole Nagel
-Karen Hines (One of Doug's Girlfriends also Doug's dad's boss) - Marg Helgenberger
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-Diane Leeds (Hospital Risk Management and one of Doug's Girlfriends) - Lisa Zane
-Jake Leeds (Diane's Son) - Zachary Browne
-Gretschn (One of Doug's Girlfriends) - ?
-Mlungisi (An old boyfriend (?) of Carries from Africa. Turns up once Series 2) - ?
-Liz (Has a brief relationship wife Carter) - Liz Vassey
-Al Grabarsky (Police Officer, Marries Lydia) - Mike Genovese
-Iris (Infomercial Director that dated Mark) - Joanna Gleason
-Heather Morgan (One of Marks patients, then briefly dated him) - Caitlin Dulany
-Kathy Snyder (Hospital Legal Counsel) - Meghan Gallagher
-Dr Swanson (A retired pathologist, admitted Series 4 Episode 18 following a traffic accident,
    has a oesophageal volvulus. Operated on laproscopically by Morgenstern and Benton but it goes
    wrong and he dies.) - Robert Ellenstein
-Zoe (Pregnant teenager. Series 4 Episode 19. Admitted following a bomb at a womans
    center. Has a Pulmonary Embolism, she is brain dead and is kept alive on a ventilator until her
    baby can be delivered) - Sally Livingstone
-Donny (Zoes boyfriend and babies father. Disliked
    by Zoes parents)- Judd Trichter
-Herb Spivak (Marks Lawyer) - Dan Hedaya