Frances Dee as Allison Lang

Brian Donlevy as Duffy Giles

Charles Butterworth as Felix

Helen Westley as Mrs. Hargraves

Henry Stephenson as Professor Jerome Hargraves

Sara Haden as Henrietta Hargraves

Etienne Girardot as Dr. Cotton

Gavin Muir as Dr. Barth

Paul Stanton as District Attorney

Julius Tannen as City Editor

Nigel De Brulier as Dr. Hall

Hilda Vaughn as Bertha

Philip Sleeman as Carl

William Ingersoll as Judge

Paul McVey as Coroner

Bruce Mitchell as Police Sergeant

John Carradine as Sanatorium Inmate (voice) (uncredited)

Don Rowan as Juror (uncredited)

Harry Strang as Court Attendant (uncredited)

Andrew Tombes as Jury Foreman (uncredited)