Before David Wenham was cast as Carl, Paul Hogan was reportedly considered for the role.
So that the production company can hold certain rights to the character, the original character from the Dracula series Abraham Van Helsing was changed to the new 'kid brother' Gabriel Van Helsing instead.
Shuler Hensley, playing Frankenstein's Monster, also stood in as a body double for the CG Mr. Hyde for fight scenes between him and Van Helsing. Shuler wore a cardboard cutout with Mr. Hyde's face on top of his head so Hugh Jackman could have a point of reference when looking at his face.
Dr. Frankenstein's lab was equipped with antique medical equipment purchased on eBay.
While preparing for the ballroom scene, Stephen Sommers had Richard Roxburgh, Kate Beckinsale and Elena Anaya practice dancing for hours every day so their performance would be flawless.
Hugh Jackman had hair extensions added for filming.
During filming, Hugh Jackman accidentally broke an extra's hand.
Cans delivering the film to theaters were labeled "The Vatican Detective".