Anthony Edwards Dr. Mark Greene Actor George Clooney Dr. Doug Ross Actor Eriq La Salle Actor Noah Wyle Dr. John Carter Actor Julianna Margulies Head Nurse Carol Hathaway Actor Gloria Reuben Jeanie Boulet Actor Laura Innes Dr. Kerry Weaver Actor Alex Kingston Dr. Elizabeth Corday Actor Kellie Martin Lucy Knight Actor John Aylward Guest Star Valerie Mahaffey Joi Abbott Guest Star Kyle Chambers Ricky Abbott Guest Star Katherine Kousi Ms. Steboff Guest Star Marlee Matlin Sign Language Instructor Guest Star Ed Lauter Fire Captain Dannaker Guest Star Christine Healy Hospital Administrator Harriet Spooner Guest Star Conor O'Farrell Richard Abbott Guest Star James Handy Dan Sullivan Guest Star Billy Blanks Kickboxing Instructor Guest Star Tom Gallop Dr. Roger Julian Guest Star Michael Crichton Executive Producer John Wells Executive Producer