Sherlock Holmes
Basil Rathbone
Doctor Watson
Nigel Bruce
Cady
Bradley Page
George
Clarence Muse
Mrs. Pettibone
Mary Forbes
Mr. Ahrens
Holmes Herbert
Sen. Henry Babcock
Thurston Hall
Antiques Store Sales Clerk
Ian Wolfe
Army Inspector (uncredited)
John Burton
Alfred Pettibone
Gerald Hamer
Sir Henry Marchmont (uncredited)
Gilbert Emery
Miss Pringle (uncredited)
Margaret Seddon
Nancy Partridge
Marjorie Lord
Party Pianist (uncredited)
Mary Field
Hotel Doorman (uncredited)
Colin Kenny
Mrs. Ruxton
Caroline Frances Cooke
William Easter
Henry Daniell
Heinrich Hinckel aka Richard Stanley
George Zucco
Naval Lt. Pete Merriam
John Archer
Mr. Lang, government agent
Gavin Muir
Detective Lt. Grogan
Edmund MacDonald
Howe
Don Terry
Mrs. Hudson
Mary Gordon
Music
Frank Skinner
Characters
Arthur Conan Doyle
Director
Roy William Neill
Producer
Writer
Bertram Millhauser
Screenplay
Lynn Riggs
Original Story
Director of Photography
Lester White
Associate Producer
Howard Benedict
Editor
Otto Ludwig
Art Direction
Jack Otterson
Set Decoration
Russell A. Gausman
Costume Design
Vera West
Assistant Director
William Tummel