Boris Karloff as Baron Viktor von Frankenstein

Jana Lund as Carolyn Hayes

Don 'Red' Barry as Douglas Row

Charlotte Austin as Judy Stevens

Rudolph Anders as Wilhelm Gottfried

Tom Duggan as Mike Shaw

Irwin Berke as Inspector Raab

John Dennis as Morgan Haley

Norbert Schiller as Shuter

Mike Lane as Hans Himmler / The Monster

Franz Roehn as Cab Driver (uncredited)

Joe Ploski as Station Porter (uncredited)

Jack Kenney as Assistant Cameraman (uncredited)

Otto Reichow as Atomic Reactor Expert (uncredited)