Basil Rathbone
Sherlock Holmes
Nigel Bruce
Doctor Watson
Marjorie Riordan
Sheila Woodbury
Rosalind Ivan
Agatha Dunham
Morton Lowry
Steward
Leslie Vincent
Nikolas Watson
Martin Kosleck
Mirko
Rex Evans
Gregor
John Abbott
Jodri
Gerald Hamer
Kingston
Frederick Worlock
Prime Minister
Tom Dillon
Matthias Cherney (uncredited)
James Carlisle
Aide (uncredited)
Olaf Hytten
Stimson (uncredited)
Gordon Jackson
Steward (uncredited)