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 Chad Lowe George Henry Guest Star Paul Kreppel Mr. Cotmeier Guest Star David Green Alan Guest Star Dan Hedaya Herb Spivak Guest Star Mariska Hargitay Guest Star Paul McCrane Robert Romano Guest Star Harold Perrineau Isaac Price Guest Star Clancy Brown Guest Star Jules Sylvester 'Jungle' Gary Loma Guest Star Conni Marie Brazelton Nurse Connie Oligario Guest Star Michael Crichton Executive Producer John Wells Executive Producer