The budget, opening weekend box office gross, and box office gross overall of this film are all virtually identical (within one million dollars) to that of House on Haunted Hill (1999), which opened almost exactly two years earlier. Both films were adapted from stories written by Robb White and originally directed by William Castle.
In the movie, the characters need special glasses see the ghosts. In the original 13 Ghosts (1960), viewers needed special glasses to see the ghosts. This is one of the few details from the original that was kept.
Shawna Loyer attracted a small cult following thanks to her brief role as the Angry Princess. A rumor circulated that the role was actually played by porn actress Aria Giovanni using a pseudonym, but this is incorrect (Ms. Giovanni was in an adult parody titled Thirteen Erotic Ghosts (2002).
Dennis said that the walls of the house were soundproof, but when he is trapped in the room with one of the ghosts, Maggie is yelling at him to move and duck. He can clearly hear her, and she can hear him, even though he isn't supposed to be able to.
The thirteenth ghost is supposed to be "The Broken Heart" which is to be a human sacrifice. It is to be "a ghost created out of love." This ghost was supposed to be Arthur sacrificing his life for his children, however, Arthur was told this would close the eye of hell whereas it would actually be the ghost that completes the spell and opens the eye. The machine needed a ghost to be created to complete the spell.