Henry Daniell, who plays Professor Moriarty in the film, had an earlier villainous role as William Easter in Sherlock Holmes in Washington, and as an ally of Holmes, Anthony Lloyd, in Sherlock Holmes and the Voice of Terror.
Norman Ainsley is listed playing an electrician in studio records, but he was not seen in the movie.
Although "The Woman in Green" is credited as an original story, dialogue is lifted from Arthur Conan Doyle's "The Final Problem," and the situation involving the sniper firing at Holmes' silhouette is taken from the next story in the original canon, "The Empty House."
Although he is not seen, the only reference to Mycroft Holmes in the Basil Rathbone / Nigel Bruce series is made in this film.
One of several titles in the Sherlock Holmes series whose original copyrights were apparently not renewed and have thereby fallen into public domain; as a result, seriously inferior copies are presently being offered by a number of VHS and DVD dealers who do not have access to original studio masters.
The Breen Office ordered two cuts from the original script. First, the victims were supposed to be young girls. That was ordered to be changed to young women although Dr. Simnell's bizarre doll fetish may be a leftover from the initial concept. In addition, during the scene in the Mesmer Club, Watson was supposed to take off his pants, not just roll up his pant leg.
The eleventh of fourteen films based on Arthur Conan Doyle's fictional consulting detective Sherlock Holmes starring Basil Rathbone as Sherlock Holmes and Nigel Bruce as Doctor Watson.
This was the first film in Universal's Sherlock Holmes series in which the main credit for Basil Rathbone and Nigel Bruce did not list the characters they played. All previous film contained "as Sherlock Holmes" and "as Doctor Watson" with their main credit.