Due to budgetary constraints and fears about safety, most of the "wolves" in this movie are actually Belgian Shepherd Dogs whose fur has been dyed. For some of the close-up shots of Rosaleen interacting with the wolf towards the end of this movie, a real wolf was used. During the entirety of the production, only two real wolves were used.
Stanley Kubrick was so impressed by the production design on this movie that he hired Anton Furst to do the production design for his next project, Full Metal Jacket (1987).
When casting the film, casting director Susie Figgis was initially looking for a girl of around sixteen years of age to portray Rosaleen. Neil Jordan had asked for an older girl so he could make the sexual overtones of this movie more pronounced. However, upon seeing the twelve-year-old Sarah Patterson's audition, Jordan felt her potential couldn't be improved upon and, due to her age, he re-wrote parts of the screenplay for her.
Neil Jordan didn't hold auditions for the part of Granny. Once the project was up and running, he offered it directly to Angela Lansbury.
Neil Jordan had wanted Andy Warhol to play the role of the Devil. Producer Stephen Woolley travelled to New York City to meet Warhol, who had recently been shot, and Warhol agreed to do this movie. However, fearing for his life if he traveled, he would only play the role if his scenes were shot in New York City. This was impossible, so Jordan cast his friend Terence Stamp in the role. Stamp agreed to do the role if Jordan bought him a suit, which he did, much to Stamp's amusement.