The scene in which a car is thrown over a cliff was initially intended to be far more spectacular - the car was to fly over the cliff and crash down to the ground. Unfortunately, the sling rope snapped because effects crew members neglected to remove the stoppers from underneath the car's wheels. The result was what is seen in the final film, the car slowly tumbles over the edge and becomes caught on a tree.
The $2 million budget went primarily on production costs. The clowns and visual effects were created almost entirely by the filmmakers at very little cost.
The Dickies, the band who wrote and performed the film's theme song, had actually not seen the film prior to writing the song.
Though not a hit when it was in theaters, the film has since become a cult classic and made revenue in action figures, DVDs, and t-shirts as well as an assortment of animatronics and other decorations from Spirit Halloween.
As John Massari returned the music master tapes to the studio, people in the accounting and legal department completely dismissed Killer Klowns as being, "A complete failure that will die a quick death." Massari responded: "Well... YOU don't get it! There are people that will LOVE this movie."