Stephen Sommers deliberately chose to avoid the style of transformations from other werewolf films, where the character would usually grow hair as part of the change. Instead the decision was made to have the character rip his skin off to reveal the werewolf form underneath, going with the idea that the beast "comes from within".
Despite popular online rumors stating this was originally planned as a direct sequel to Dracula (1992) with Anthony Hopkins reprising his role, this is not the case. Stephen Sommers thought up the concept for the film while vacationing after he had completed The Mummy Returns (2001).
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.
The effect of the vampire brides' flying forms was pulled off by having the face and hair of the actresses made up as it would appear in the film and having them wear motion capture suits and film them against green screen. The appearance of the three brides is based on the brides in Dracula (1992). Ironically, Silvia Colloca played the queen bride as Monica Bellucci did and the two have been compared often. Also, the fair haired vampire (Marishka) dies first in both movies.
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.
Director Stephen Sommers claimed in an interview he changed the main character's name from Abraham Van Helsing to Gabriel Van Helsing, as he did not think he could have a lead character named Abraham. The Irishman who wrote Dracula, Bram Stoker, named the character after himself - Bram being a shortening of Abraham.
While the film is an homage to the 1930s and '40s Universal Monster horror films, the inclusion of Mr. Hyde is an oddity, as he was never one of the Universal Monster roster. Instead, the films based on Hyde during that time were made for Universal's rival MGM. However, in 1953, Universal did feature the monster in the comedy Abbott and Costello Meet Dr. Jekyll and Mr. Hyde (1953).
The place where Van Helsing and Anna fight Dracula's three wives is the same place where they filmed Frankenstein (1931)Dracula (1931) and The Wolf Man (1941). The place is call the Court of Miracles and this place is also found at the studio tour at Universal Studios Hollywood.
Stephen Sommers wanted Kate Beckinsale for the role of Anna, but feared it was too similar in tone to the vampire/werewolf film Underworld (2003) which she was shooting at the time, and he didn't ask her. Eventually her agent got Sommers to send the script and Beckinsale immediately signed on.
A spin-off TV series was pitched to NBC. To have been called "Transylvania", it was to have featured a wild-west sheriff taken to Europe to battle monsters, with occasional guest appearances by Hugh Jackman as Gabriel Van Helsing. The series idea was stillborn, partly because makeup, effects, and location shooting in Romania would have been too expensive, and partly because the film's opening weekend box office was far below expectations (which also doomed a proposed sequel to the film).
The film was storyboarded and previsualized with the intent of shooting the film in the anamorphic 2.35:1 format, like Stephen Sommers' previous films. The aspect ratio was changed to 1.85:1 in order to better accommodate Dracula's vertically-oriented castle without having to extend the sets.
Shuler Hensley reprised his role of Frankenstein's Monster in Mel Brooks's stage adaptation of Young Frankenstein (1974). Costarring Roger Bart as Dr. Frederick Frankenstein, the play opened at the Hilton Theater, New York City on November 8, 2007. It closed on January 4, 2009 after 29 previews and 485 performances.
At some point in pre-production, a cameo appearance by the Gil-Man from Creature from the Black Lagoon (1954) was slated to appear in the underground cave where Van Helsing and Anna discover Frankenstein's Monster. However, this idea was dropped before filming began. (Stephen Sommers was once rumored to be attached to a remake of "Creature...")
Was intended to kick off a series of "Van Helsing" adventure movies; however, reviews were bad and the box office returns were far below expectations, so all plans for a sequel were dropped within days of the film opening.
The trivia items below may give away important plot points.
One of the last shots in which Van Helsing transforms back into a human from a werewolf was originally to be a nude scene (for Hugh Jackman), however Stephen Sommers felt that it would have been too distracting to the viewer and disrupt the emotion of Anna's death from the scene. The nude shot is still used in the film, however a CGI loin cloth was animated to cover Jackman's rear.
The last scene shot for actor Will Kemp was actually his death scene. It was filmed in Griffith Park in Los Angeles, California. In the scene he is to lay against a rock. What the crew did not know was that there were a lot of spiders in the area and when Kemp's scene was finally completed, he went home with many spider bites on his back and arms.