Lyle Talbot as Lt. Bob Bennett

Irving Pichel as Dr. Herbert Stander

Julie Bishop as Joan Martel

Sheila Bromley as Poison Mary Slavish

Anthony Averill as Dirk - Stander's Aide

Russell Hopton as Harry 'The Carver' Bogard

Julian Madison as Paul - Stander's Aide

Eddie Holden as Ole Olson

Wheeler Oakman as John Ritter

Stanley Blystone as Capt. Mike Briggs

Leander De Cordova as Ezra Matthews

Demetrius Alexis as Steve Murano

Skelton Knaggs as Jesse Bixel

Carleton Young as Reporter

William N. Chapman as Bill

Jack Gardner as Reporter

Adia Kuznetzoff as Adolph Krantz

Bert LeBaron as Sailor

Fred Walton as Dr. Beemish