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 CCH Pounder Guest Star Yvette Freeman Guest Star Jorja Fox Dr. Maggie Doyle Guest Star Harry Lennix Dr. Geg Fischer Guest Star Veronica Cartwright Norma Houston Guest Star Chad Lindberg Jad Houston Guest Star Jami Gertz Guest Star Caitlin Dulany Heather Morgan Guest Star Ellen Crawford Guest Star Clea Duvall Katie Reed Guest Star Cynthia Lamontagne Paula McKenzie Guest Star Khandi Alexander Jackie Robbins Guest Star Tim Bagley Archie Papion Guest Star Daniel T. Parker Kevin Guest Star Craig Thomas Roger Guest Star Michael Crichton Executive Producer John Wells Executive Producer