Roddy McDowall as Alan Musgrave

Tuesday Weld as Barbara Ann Greene

Lola Albright as Marie Greene

Martin West as Bob Bernard

Ruth Gordon as Stella Bernard

Harvey Korman as Weldon Emmett

Sarah Marshall as Miss Schwartz

Lynn Carey as Sally Grace

Donald Murphy as Phil Neuhauser

Max Showalter as Howard Greene

Joseph Mell as Dr. Milton Lippman (as Joe Mell)

Dan Frazer as Honest Joe

Martine Bartlett as Inez

Jo Collins as Kitten

Judith Loomis as Butch Neuhauser

David Draper as Billy Gibbons

Peter Adams as Frank (uncredited)

Martin Gabel as T. Harrison "Harry" Belmont (uncredited)