Tony Curtis as Harry Erskine

Michael Ansara as John Singing Rock

Susan Strasberg as Karen Tandy

Stella Stevens as Amelia Crusoe

Jon Cedar as Dr. Jack Hughes

Ann Sothern as Mrs. Karmann

Burgess Meredith as Dr. Snow

Paul Mantee as Dr. McEvoy

Jeanette Nolan as Mrs. Winconis

Lurene Tuttle as Mrs. Herz

Hugh Corcoran as MacArthur

Anne Newman Bacal as 10th-Floor Nurse

Jan Heininger as Wolf, an orderly

Michael Laren as Michael, an orderly

Cindy Stanford as Neighbor

Felix Silla as Misquamacus

Charles Kissinger as Anesthesiologist