Boris Karloff

as James Lee Wong

Grant Withers

as Police Capt. Sam Street

Dorothy Tree

as Valerie Edwards

Craig Reynolds

as Peter Harrison

Ivan Lebedeff

as Michael Strogonoff

Holmes Herbert

as Prof. Ed Janney

Morgan Wallace

as Brandon Edwards

Lotus Long

as Drina

Chester Gan

as Sing

Hooper Atchley

as Carslake

Bruce Wong

as Asian Man

Jack Kennedy

as Police Guard

Lee Tung Foo

as Willie

Wilbur Mack

as Ballstics Expert

Dick Morehead

as Police Detective

Joe Devlin

as Police Lt. George Devlin

I. Stanford Jolley

as Charades-Player