Henry Victor
Professor Frederic Hoffner (uncredited)
Lionel Atwill
Professor Moriarty
Mary Gordon
Mrs. Hudson
Nigel Bruce
Doctor Watson
Paul Fix
Mueller (uncredited)
Basil Rathbone
Sherlock Holmes
Whit Bissell
London Bobbie (uncredited)
Dennis Hoey
Inspector Lestrade
Holmes Herbert
Sir Reginald
Paul Bryar
Swiss Waiter (uncredited)
Kaaren Verne
Charlotte Eberli
William Post Jr.
Dr. Franz Tobel
Harry Cording
Jack Brady (uncredited)
Harry Woods
Kurt (uncredited)
Colin Kenny
Scotland Yard Detective (uncredited)
Rudolph Anders
Braun (uncredited)