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 Bonnie Bartlett Ruth Greene Guest Star John Cullum David Greene Guest Star Patti Allison Motel Manager Guest Star Frank Califano Priest Guest Star James Dalesandro Mexican Man Guest Star George "Buck" Flower Lamont Guest Star Rick Cramer McCormick Guest Star Aldo Menjivar Nacho Guest Star Sonia Iris Lozada Mrs. Lopez Guest Star Michael Crichton Executive Producer John Wells Executive Producer