Jeff Celentano was once rumored to direct the film.
Before Paris Hilton was cast as Paige Edwards, Jennifer Connelly and Kate Winslet were originally considered for the role. The rest of the cast was built around her. Her "That's hot" catchphrase is spoken by several characters, for this reason.
Names mentioned in the script but not the film are the roadkill collector (Lester), and Carly and Nick's last name (Jones). Chad Michael Murray (Nick), in a radio interview, was shocked to hear his character finally had a last name, and said that it was an ongoing debate on set.
In the movie theatre where Carly and Nick are hiding, most of the wax figures were actually extras wearing masks.
Elisha Cuthbert got stuck repeatedly in the melting wax bed while filming the final scenes of the movie. The "wax" was actually peanut butter.
The death of Paris Hilton's character was originally longer and featured more gore but it was cut for the theatrical release.
Jared Padalecki is one foot taller than co-star Elisha Cuthbert. To make herself appear taller in scenes where she and Padalecki would be filmed together, Cuthbert taped two-inch blocks of wood to the bottoms of her boots. This was only done during scenes where they would be shot from the knee and up.
In the church where Carly hides, as well as the movie theatre where Carly and Nick are hiding, most of the wax figures were actually extras wearing masks.
Warner Brothers granted Paris Hilton permission to sell t-shirts that read "On May 6th, Watch Paris Die" in order to promote the film before its release.
The town of Ambrose was constructed in 10 weeks, and was modeled after a real town in Ethiopia called Asmara. Asmara was built by the Italians in Africa during World War II in the Modern Style rather than the Deco Style, which was more popular at the time.
While filming the abandoned sugar mill chase, Paris Hilton was embarrassed by her scream, so the first three times she screamed she had the whole cast and crew scream along with her.
On 26 June 2004, a sound stage being used for the film burned to the ground during a test of special-effects equipment. The fire, started by a candle, destroyed a studio at Warner Bros Movie World on Australia's Gold Coast. One crew member was treated for burns to his arm, but no one else was injured. The smoke reached a nearby highway, which was not shut down.