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 Omar Epps Actor Laura Innes Dr. Kerry Weaver Actor Ron Eldard Ray 'Shep' Shepard Guest Star Lisa Nicole Carson Guest Star Khandi Alexander Jackie Robbins Guest Star Ellen Crawford Guest Star Yvette Freeman Guest Star Ving Rhames Walter Robbins Guest Star Michelle Clunie Gretchen Guest Star Karen Hensel Keller Guest Star Stephen Rappaport Matthew Hyams Guest Star Michael Crichton Executive Producer John Wells Executive Producer