Pérola Negra

Basil Rathbone

Sherlock Holmes

Nigel Bruce

Dr. John Watson

Dennis Hoey

Inspector Lestrade

Evelyn Ankers

Naomi Drake

Miles Mander

Giles Conover

Ian Wolfe

Amos Hodder

Charles Francis

Francis Digby, curator

Holmes Herbert

James Goodram, courier

Richard Aherne

Museum Guard Bates

Mary Gordon

Mrs. Hudson

Rondo Hatton

The Hoxton Creeper

Harry Cording

George Gelder (uncredited)

Billy Bevan

Constable With Food Tray (uncredited)

Leyland Hodgson

Customs Officer (uncredited)

Eric Wilton

Chauffeur (uncredited)

Lillian Bronson

Maj. Harker's Housekeeper (uncredited)