Bela Lugosi

Prof. Dexter

John Carradine

Prof. John Gilmore

Frank Moran

Ape Man

Teala Loring

Anne Gilmore

Tod Andrews

Steve Rogers

Mary Currier

Hilda Gilmore

Ernie Adams

Tramp, Willie the Weasel

Eddy Chandler

Sergeant

George Zucco

Ape Man

Mike Donovan

Policeman Barney (uncredited)