Elenco
Basil Rathbone
Sherlock Holmes
Nigel Bruce
Dr. John Watson
Hillary Brooke
Lydia Marlowe
Henry Daniell
Professor James Moriarty
Paul Cavanagh
Sir George Fenwick
Matthew Boulton
Inspector Gregson
Eve Amber
Maude Fenwick
Frederick Worlock
Dr. Onslow
Percival Vivian
Dr. Simnell
Coulter Irwin
Corporal Williams
Sally Shepherd
Crandon
Mary Gordon
Mrs. Hudson
John Burton
Waring the Mesmerist (uncredited)
Harold De Becker
Shoelace Vendor Henchman (uncredited)
Tony Ellis
Carter the Hypnotized Subject (uncredited)
Bess Flowers
Bar Patron (seen in mirror) (uncredited)
Kay Harding
4th Victim (uncredited)
Alec Harford
Commissioner of the CID (uncredited)
Olaf Hytten
Fenwick's Butler Norris (uncredited)
Boyd Irwin
Short-Tempered Officer Closing Window (uncredited)
Eric Mayne
Member of Mesmer Club (uncredited)
William H. O'Brien
Pembrook House Waiter (uncredited)
Equipe
Edward Curtiss
Editor
Vera West
Costume Design
Virgil Miller
Director of Photography
Russell A. Gausman
Set Decoration
Roy William Neill
Producer
John P. Fulton
Special Effects
Roy William Neill
Director
John B. Goodman
Art Direction
Melville Shyer
Assistant Director
Bertram Millhauser
Screenplay
Ted von Hemert
Set Decoration
Bernard B. Brown
Sound Director
Mark Levant
Music Director
Martin Obzina
Art Direction
Roswell A. Hoffmann
Camera Operator
Arthur Conan Doyle
Novel