Charles Chaplin called Lorre the screen's best actor after seeing his performance in "Mad Love."
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.
The line "Each man kills the thing he loves" comes from Oscar Wilde's poem, "The Ballad of Reading Gaol".
You may recognize the voice of Edward Brophy, who plays convicted killer Rollo. In addition to supporting roles and character parts in dozens of well-known films, Brophy also was the voice of Timothy, the circus mouse who befriended and mentored the flying baby elephant in Walt Disney's Dumbo.
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 (1935) with him in the role of Raskolnikov.
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 (1932), 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 (1931) 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.
Ian Wolfe, who played Stephen Orlac's stepfather Henry, was 38 during filming, only four years older than Colin Clive, 34, who played his stepson.
The first two lines of poetry quoted by Peter Lorre are from Elizabeth Barrett Browning's Sonnets from the Portuguese, number seven: The face of all the world is changed, I think, Since first I heard the footsteps of thy soul.
Because cinematographer Gregg Toland would later work on "Citizen Kane", film critic Pauline Kael postulated this film influenced the later masterpiece.
After its initial release, 15 minutes were cut from the film, including the pre-credit warning to the audience and the surgery to obtain Rollo's hands.
This film was directed by one of the all-time great German cinematographers, Karl Freund. One of his directors of photography on this film was one of America's all-time great cinematographers, Gregg Toland.
The following lines, quoted by Peter Lorre about halfway through the film, are taken from the first of Elizabeth Barrett Browning's Sonnets from the Portuguese: Guess now who holds thee? Death, I said, But, there, The silver answer rang, Not Death, but Love.
Other titles considered for this film included "The Mad Doctor of Paris" and "The Hands of Orlac".
The original one-sheet proclaimed that this was "SUITABLE ONLY FOR ADULTS." Of course, this was not enforced and served to boost the boxoffice.
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.
Easily recognized actors who are supposed to be in this movie according to studio records and/or casting call lists include Harold Huber, Isabel Jewell, George Davis, Billy Dooley and Leo White. However, they were not seen.