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, Director Alex Kingston Dr. Elizabeth Corday Actor Kellie Martin Lucy Knight Actor Julie Bowen Roxanne Please Guest Star Djimon Hounsou Guest Star Kyle Chambers Ricky Abbott Guest Star Matthew Glave Dr. Dale Edson Guest Star Cress Williams Officer Reggie Moore Guest Star Valerie Mahaffey Joi Abbott Guest Star Paul McCrane Robert Romano Guest Star Yvonne Zima Rachel Greene Guest Star John Aylward Guest Star Conni Marie Brazelton Nurse Connie Oligario Guest Star Laura Cerón Nurse Chuny Marquez Guest Star Michael Crichton Executive Producer John Wells Executive Producer