John Milius wrote the screenplay with Lee Marvin in mind as Judge Roy Bean. He brought the script to Marvin when he was filming Pocket Money (1972), but Marvin fell asleep after one drink too many. His co-star Paul Newman found the screenplay, read it, loved it and petitioned for the part.
When driving through Dublin in the early 1990s, Paul Newman asked his driver to stop. He had passed a restaurant called "Judge Roy Beans" and told his driver that he had to go in and see what it was like. At six o clock in the evening, patrons were more than pleased and surprised to see this veteran Hollywood star coming into the bar. He pointed at the quad poster framed on the wall and told everyone that he had played Judge Roy Bean. When the barman told him that next time he was in town, he should call into the nightclub above called Lillies Bordello, Newman immediately pointed to the image of Ava Gardner on the poster and shouted, "And she played Lillie!"
Michael Sarrazin's name in the opening credits is listed as "participation". That participation amounted to appearing in a photograph at the end of the movie, portraying the husband of Rose Bean (Jacqueline Bisset). He does not physically appear in the movie. Bisset was dating Sarrazin at the time.
Paul Newman thought that Bruno the Bear stole every scene in which they appeared together, an opinion shared by some reviewers.