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 Laura Innes Dr. Kerry Weaver Actor Christine Elise Actor Abraham Benrubi Guest Star Ron Rifkin Guest Star Kathleen Wilhoite Guest Star Marg Helgenberger Karen Hines Guest Star Mary Mara Loretta Sweet Guest Star William H. Macy Dr. David Morgenstern Guest Star David Spielberg Dr. Neil Bernstein Guest Star Carlos Gomez Paramedic Raul Melendez Guest Star Ellen Crawford Nurse Lydia Wright Guest Star Yvette Freeman Nurse Haleh Adams Guest Star Ron Eldard Guest Star Michael Crichton Executive Producer John Wells Executive Producer