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 Maria Bello Dr. Anna Del Amico Actor Michael Beach Guest Star Frances Sternhagen Millicent Carter Guest Star Taylor Negron Mr. Prole Guest Star Patrick Kilpatrick Matthew Lindermulder Guest Star Monica Parker Allergic Woman Guest Star Richard Edson Vinnie La Fontaine Guest Star Paul McCrane Robert Romano Guest Star Clancy Brown Guest Star Seth Jaffe Process Server Guest Star Shaun Toub Butler Guest Star Lily Mariye Nurse Lily Jarvik Guest Star Michael Crichton Executive Producer John Wells Executive Producer