Robert Stephens was the original choice to play Holmes. He would play the role in 1970.
Frank Finlay also plays Inspector Lestrade in Murder by Decree, another film that pits Sherlock Holmes against Jack the Ripper. Anthony Quayle appears in both movies as well, in different roles.
John Neville reprised the rôle of Holmes on Broadway in the 1970s.
John Fraser has starring billing in the main titles but does not turn up till 24 minutes in, meaning his his role is an expanded cameo rather than a leading role.
Thorley Walters was offered Dr.Watson.
Mary Kelly's one room flat was located on the first floor.
The closing Baker Street sequence alludes to Conan Doyle's 1892 short story "The Adventure of the Blue Carbuncle."
The Ripper's first victim, Mary Ann Nichols had just bought a new hat and was very proud of it on the night she was murdered. This bit of business is given to the Ripper's third victim, Long Liz Stride.