Arnold Schwarzenegger's first film since Batman & Robin (1997). The reason for the gap was because of his heart surgery after playing Mr Freeze; the studios were anxious about whether or not they could insure him, and despite attempts to convince them he was in perfect health, he couldn't get any work until End of Days (1999). Even then, he was amazed when insurance people and executives from Universal came to the set just to watch him, to see if he was still up to the action scenes. They asked Schwarzenegger if he enjoyed this kind of punishment, but he said he was used to it. After the first week of shooting, the insurance guys backed off and not long after, the film offers started rolling in again.
Years later, Miriam Margolyes revealed on a talk show she did not enjoy her first and only working experience with Arnold, citing the odd reason that in their scene together "He farted in my face!" (as she so eloquently put it).
Udo Kier claimed in an interview that he was considered for the role of Satan in the film but the producers didn't want the hero and villain to both have German/Austrian accents, and he was eventually cast in a secondary role.
One of the priests is named Thomas Aquinas. Thomas Aquinas was one of the greatest philosophers, a 13th-century proponent of natural theology and the father of the Thomistic school of philosophy and theology.
Alternate ending was filmed in which Jericho resurrects after impaling himself on the sword of the statue and then leaves the church with Christine. Test audience preferred ending where Jericho dies. Even though "resurrection" ending was never released, it was used in novelization of the movie.