• 
  Reginald Le Borg

  regizor

• 
  Gerald Drayson Adams

  scenarist
• 
  John C. Higgins

  scenarist

• 
  Basil Rathbone

  Sir Joel Cadman
• 
  Akim Tamiroff

  Odo the Gypsy
• 
  Lon Chaney Jr.

  Dr. Munroe aka Mungo
• 
  John Carradine

  Bohemund
• 
  Bela Lugosi

  Casimir

• 
  Herbert Rudley

  Dr. Gordon Angus Ramsay
• 
  Patricia Blair

  Laurie Munroe
• 
  Phyllis Stanley

  Nurse Daphne
• 
  Sally Yarnell

  Female Subject
• 
  George Sawaya

  Sailor-Subject
• 
  Claire Carleton

  Carmona Daly
• 
  Tor Johnson

  Mr. Curry

• 
  Aubrey Schenck

  Prison Coroner's Aide
• 
  Patricia Blair

  Laurie Monroe (as Patricia Blake)
• 
  Claire Carleton

  Carmona Daly
• 
  Herbert Rudley

  Dr. Gordon Angus Ramsay
• 
  Phyllis Stanley

  Daphne
• 
  Sally Yarnell

  Nancy--Female Monster

• 
  Howard W. Koch

  producător