Anthony Edwards Dr. Mark Greene Actor George Clooney Dr. Doug Ross Actor Sherry Stringfield Dr. Susan Lewis 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 Omar Epps Actor William H. Macy Dr. David Morgenstern Actor John Aylward Actor Michael Beach Guest Star Isabella Hofmann AIDS Clinic Doctor Guest Star Raye Birk Mr. Hartley Guest Star Yvette Freeman Guest Star Ellen Crawford Guest Star Eileen Brennan Betty Guest Star Rose Gregorio Helen Hathaway Guest Star Steve Vinovich Wayne Lentloff Guest Star Matt Landers Mr. Travels Guest Star Tony Carreiro Brent Smythe Guest Star Michael Crichton Executive Producer John Wells Executive Producer