Peter Lorre was under contract to Columbia Pictures. He agreed to be loaned out to MGM for this film if Columbia would do a film version of Crime and Punishment with him in the role of Raskolnikov.
The Hays Office cautioned the studio about showing scenes of the dead, injured or dying after the train wreck. Some countries banned the film altogether, while others cut the scenes of torture, guillotining and strangulation.
May Beatty's declaration about the wax figure, "It went for a little walk!" is a clear echo of a similar line from The Mummy, also written by John L. Balderston and directed by Karl Freund.
The original titles were to contain a spoken warning in a manner similar to Frankenstein also written by Balderston, but that was abandoned in favor of the more original idea of the titles on a window climaxed by a fist smashing it.
A torn poster of this movie, with its Spanish translation "Las manos de Orlac", appears in Malcolm Lowry's Under the Volcano, as a symbol for the intricate novel's plot that subsumes as dissension between mind and body of its anti-hero protagonist.
The trivia items below may give away important plot points.
In the original script the little girl dies in surgery because Gogol is so distracted. In the finished film, his mental distraction causes him to leave the operation and it is successfully completed by Dr. Wong.