Jacques Bergerac as Desmond

Merry Anders as Dodie Wilson

Marcia Henderson as Marcia Blaine

Allison Hayes as Justine

Joe Patridge as Det. Sgt. Dave Kennedy

Fred Demara as The Great Impostor

Lawrence Lipton as Beatnik Poet Laureate

Eric Nord as King of the Beatniks (as Eric 'Big Daddy' Nord)

Guy Prescott as Dr. Philip Hecht

Jimmy Lydon as Emergency Doctor (as James Lydon)

Carol Thurston as Doris Scott

Eva Lynd as Woman from Audience

Eddie Baker as Observer at Scene (uncredited)

Nina Borget as Audience Member (uncredited)

Phyllis Cole as Mrs. McNear (uncredited)

Franklyn Farnum as Audience Member (uncredited)

Mary Foran as June Mayes (uncredited)

George Ford as Audience Member (uncredited)

Holly Harris as Mrs. Stevens (uncredited)

Kenner G. Kemp as Audience Member (uncredited)

Evan MacNeil as Victim (uncredited)

Monty O'Grady as Audience Member (uncredited)

Al Roberts as Audience Member (uncredited)

Cosmo Sardo as Theatre Greeter (uncredited)