Sean Connery's career was at such a low point when he read for the role that Columbia Pictures refused to finance the movie when Jean-Jacques Annaud cast him as William von Baskerville.
According to Ron Perlman, director Jean-Jacques Annaud had purposely not written a lot of the movie's dialogue, in order to more easily secure funding. When they started filming however, he wanted Perlman to talk in all his scenes. Since Salvatore was described as a character who speaks "six languages at once" (among them Latin, Italian, German, English, and French), Perlman got copies of the book in all of those languages. He then composed mixed-language sentences by combining words from Salvatore's sentences from each book.
William von Baskerville is amazed when he discovers a book by "Umberto of Bologna", a reference to Umberto Eco, who teaches at the University of Bologna, and is the author of the book on which this movie was based.
Christian Slater had nothing but praise for his co-star Sean Connery. He described working with Connery "like having a master class in acting, life, all sorts of things. He's an incredible professional, a real gentleman, a man's man." He also said that Connery was extremely involved in every detail of filming, and at one point scolded the on-set horse wrangler for mistreating the animals. Ron Perlman had similarly fond memories of Connery's mentoring skills and meticulous preparation, and added that Connery would "basically sit there for eight hours between shots and download [stories about Hitchcock and John Huston and all the people he'd worked with] onto me, and see the delight coming out of me." Perlman even came to the set on his days off, just to see Connery work.
Director Jean-Jacques Annaud admitted to casting the ugliest actors he could get, because he wanted the characters to appear "real", based on the men in the village where he lived. When he returned to his village, some of the men asked him if he really considered them to be as ugly as the actors, and he said, "Yes."