Cast of ER Cast of ER "ER" is an American drama series that aired on NBC from September 19, 1994 until April 2, 2009. The series featured a large ensemble cast that changed dramatically over its long run. The main cast was augmented by a wealth of recurring characters and award-winning guest stars. The original starring cast consisted of Anthony Edwards as Dr. Mark Greene, George Clooney as Dr. Douglas "Doug" Ross, Sherry Stringfield as Dr. Susan Lewis, Noah Wyle as medical student (later Dr.) John Carter, and Eriq La Salle as Dr. Peter Benton. Julianna Margulies guest starred in the pilot as
ER (TV series) ER (TV series) ER is an American medical drama television series created by novelist and medical doctor Michael Crichton that aired on NBC from September 19, 1994, to April 2, 2009, with a total of 331 episodes spanning over 15 seasons. It was produced by Constant c Productions and Amblin Television, in association with Warner Bros. Television. "ER" follows the inner life of the emergency room (ER) of fictional County General Hospital in Chicago, Illinois, and various critical issues faced by the room's physicians and staff. The show became the longest-running primetime medical drama in American television history, also became