John Carl Buechler was considered to direct the film. His version of the story was going to be a straight up horror film. The Garbage Pail Kids would have spawned from radioactive sludge that had found its way to a garbage can filled with broken dolls, turning them into serial killers.
Mackenzie Astin auditioned and signed onto the movie without telling his father, actor John Astin. When he was informed and given the script by his son, John thought the script was so bad he looked into getting Mackenzie out of the film.
The Garbage Pail Kid facial puppet heads required more detail work for facial animation prior to filming. The effects team didn't complete the heads on time. Rod Amateau made the film anyway, expecting the puppet head effects to improve during filming.
Mackenzie Astin and Katie Barberi were dating in real life. They broke up in the middle of shooting.