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 Abraham Benrubi Jerry Markovic Guest Star Zachary Browne Jake Leeds Guest Star Amy Aquino Dr. Janet Coburn Guest Star Debra Jo Rupp Mrs. Dibble Guest Star Christine Harnos Guest Star Andrea Parker Linda Farrell Guest Star Gloria Reuben Jeanie Boulet Guest Star Kathleen Wilhoite Chloe Lewis Guest Star Lisa Zane Diane Leeds Guest Star Michael Ironside Dr. William 'Wild Willy' Swift Guest Star Charles Boswell 'Dr.' Lyle Strong Guest Star Karl David-Djerf Charles Caffee Guest Star Jean Marie Barnwell Samantha Guest Star Brianne Prather Katie Nemeth Guest Star David Selburg Dr. Dyer Guest Star Michael Crichton Executive Producer John Wells Executive Producer