Trivia

This is the only werewolf film made by "Hammer Studios."

According to the documentary "Flesh and Blood: The Hammer Heritage of Horror (1994)" the Spanish setting for this film was forced upon writer Anthony Hinds after Michael Carreras had the studio back-lot dressed for a film about the Spanish Inquisition. This film was not produced because the Catholic League of Decency threatened to ban it.

The film forgoes the more popular (and 20th century) myth that a person bitten by a werewolf will become one. Instead, it invokes the much older idea that a child born on Christmas Day will be the victim of the lupine curse. In many European countries, it was believed that such a child was competing with the assumed birth of Jesus Christ and that the curse was a punishment for blasphemy.

The interiors of the inn where Leon is staying is the same interior from Dracula's castle in "Dracula (1958)." You can notice the same pillars. The basement he runs into is also the same vault where Dracula kept his coffin.

In an interview, Richard Wordsworth stated that in the original screenplay his beggar character was a werewolf. "Hammer" told him that the censor had problems with the notion of a werewolf/rapist, so out it went.