Martin Shaw (Sir Henry Baskeville) is dubbed by American actor Kerry Shale.
Denholm Elliott (Dr. Mortimer) previously played Stapleton in the spoof O Cão dos Baskervilles (1978).
Producer Sy Weintraub had paid a considerable amount for the Sherlock rights only to discover that Granada TV had also been given permission to film the Holmes stories with Jeremy Brett starring. A subsequent court case found in Weintraub's favor and he decided to abandon plans to film any more of Conan Doyles stories .
Rather bafflingly, the character of Inspector Lestrade is introduced far earlier in the story in this version than he is in the novel, but is left out of the scene of Holmes and Watson confronting and killing the hound - the one scene in the book in which he appears.
The character of "Geoffrey Lyons" does not appear in the original novel, nor is there any equivalent character. The scene where he bends a poker to impress Holmes with his strength is derived from another Sherlock Holmes story, "The Speckled Band".