Anthony Edwards Dr. Mark Greene Actor George Clooney Dr. Doug Ross Actor Eriq La Salle Dr. Peter Benton 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 Paul McCrane Robert Romano Guest Star Ashley Johnson Dana Ellis Guest Star Penny Johnson Nurse Practitioner Lynette Evans Guest Star Matthew Glave Dr. Dale Edson Guest Star Sam Anderson Dr. Jack Kayson Guest Star Freda Foh Shen Audiologist Guest Star Richard Gant Mr. Lipson Guest Star Jeff Cahill Transport Dispatcher Tony Fig Guest Star Tommy Hinkley Mr. Ellis Guest Star Jermaine Montell Bo Guest Star Franc Ross Naughton Guest Star Claire Yarlett Claudia Olson Guest Star Michael Crichton Executive Producer John Wells Executive Producer