Director Ron Howard wasn't happy with Nicole Kidman's facial reaction during the shooting of the scene where her character lifts the bowl covering Joseph's (her husband Tom Cruise's) crotch. Without telling Kidman, he asked Cruise to remove his underwear. Howard got the reaction he wanted, and it appears in the film.
Although he had over 17 years of experience in the business in 1992, this film marked the first time that dialect coach Tim Monich had to teach his cast to speak in an Irish accent. Technically, Nicole Kidman's accent is incorrect. As a well-to-do landowner's daughter in Ireland at the time, she would have spoken with a largely English accent, but, as this probably would have confused international audiences, she was taught to speak in an educated Dublin accent.
The boxing scenes were filmed in the partially renovated train station in Billings, MT. An abandoned Price Club in Billings served as both a factory to produce rubber chickens used in the movie and a soundstage for the brothel. The brothel was built inside, and fire pumps were used to create rain.