Trivia

In Curt Siodmak's original script for the film, whether or not Lawrence Talbot really underwent a physical transformation to a werewolf or if the transformation simply occurred in his mind was left ambiguous. The Wolf Man was never to appear onscreen. Ultimately, the studio determined that Talbot's literal transformation into a werewolf would be more appealing to the audience and, thus, more profitable. The script was revised accordingly. The remake of the film starring Benicio Del Toro leaned into this idea, having its version of Lawrence Talbot be admitted to an asylum for "delusions" of lycanthropy.

Bela Lugosi actively campaigned for the lead role and ended up playing a minor supporting role.

The "wolf" that Larry Talbot fights with was Lon Chaney Jr.'s own German Shepherd.

Evelyn Ankers suffered a bad scare when a 600-pound bear (His sequence in the film was later cut.) escaped its trainer and chased the actress up a ladder, where she was pulled to safety by an electrician.

The Wolf Man battled a bear in one scene, but unfortunately the bear ran away during filming. What few scenes were filmed were put into the theatrical trailer.