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 Michael Beach Guest Star Glenne Headly Guest Star Deborah May Mary Cain Guest Star Anne-Marie Johnson Sickle-Cell Patient Guest Star Ellen Crawford Guest Star Yvette Freeman Guest Star Kevin Carroll Clerk Guest Star Martin Grey Mr. Wilbourne Guest Star Conni Marie Brazelton Nurse Connie Oligario Guest Star Deezer D Nurse Malik McGrath Guest Star Kristin Minter Randi Fronczak Guest Star Michael Crichton Executive Producer John Wells Executive Producer