Lew Ayres (Oliver Duffy)
Laraine Day (Edwina Brown)
Basil Rathbone (Dr. H. Santelle)
Walter Kingsford (Dr. Cromwell)
Miles Mander (Dr. Kurt Immelman)
Iris Adrian
Hooper Atchley
William Tannen (Devlan)
Mark Daniels (Haguey)
Bert Roach (Krum)
Russell Hicks (Dr. Chandley)
Charles Wagenheim (Fred Bixley)
Robert E. Homans (Officer O'Garrity)
Charles D. Brown (Inspector Gallagher)
Cliff Clark (Lieutenant Allison)
James Flavin (Lieutenant Schaeffer)
Russell Gleason (Ogilivie)