- Dodger (Played by Mackenzie Astin) is a young fourteen-year-old boy who was bullied by Juice. He met the Garbage Pail Kids and is the film's protagonist.
- Captain Manzini (Played by Anthony Newley) is the owner of the store that the Garbage Pail Kids were captured and where Dodger worked at. He is the film's deuteragonist.
- Tangerine (Played by Katie Barberi) is Juice's girlfriend and who Dodger wanted to be his girlfriend.
- Juice (Played by Ron MacLachlan) is the film's main antagonist. He is a bully who bullies Dodger for no reason.
- Wally (Played by J.P. Amateau) is Juice's henchman.
- Blythe (Played by Marjory Graue) is Juice's henchwoman.
- Ali Gator (Played by Kevin Thompson) is one of seven Garbage Pail Kids.
- Foul Phil (Played by Bobby Bell, Voiced provided by Chloe Amateau) is the second of seven Garbage Pail Kids.
- Nat Nerd (Played by Larry Green, Voice provided by Jim Cummings) is the third of seven Garbage Pail Kids.
- Greaser Greg (Played by Phil Fondacaro, Voice provided by Jim Cummings) is the fourth Garbage Pail Kid.
- Windy Winston (Played by Arturo Gil) is another Garbage Pail Kid and the fifth of seven.
- Messy Tessie (Played by Susan Rossitto, Voice provided by Teri Benaron) is the sixth Garbage Pail Kid.
- Valerie Vomit (Played by Debbie Lee Carrington) is the seventh and last Garbage Pail Kid.
- Banana Anna (Mentioned) never appeared in the film.
- Ultra Violet (Mentioned) never appeared in the film either.
The story begins with the opening credits showing GPK cards flying in outer space, showing the main characters of the film. A trash can-shaped spaceship lands on Earth. We cut to the inside of an antique store with a Garbage Pail. The kids exit the pail and try to wreak havoc and have fun, but they get back in before Captain Manzini catches them. Manzini suspects that things haven't been normal, so he proceeds to put a diving helmet on top of the garbage pail to keep the kids from getting out again.
The next day, a young boy named Dodger is bullied by Juice and his gang and gets knocked into a mud puddle. Juice's girlfriend Tangerine is annoyed that her boyfriend is picking on a young boy for no good reason. After going back to Captain Manzini's antique store, where Dodger has a part-time job, Manzini washes Dodger's clothes and gives him a dashiki to wear, which was given to him by an African tribal leader named Um-Tuh-Tuh in exchange for making his mother-in-law disappear. While fooling around with a rapier, Dodger nearly knocks off the diving helmet keeping the garbage pail shut, but is stopped by Captain Manzini, who proceeds to tell him to leave the pail alone, comparing it to Pandora's Box of Greek Mythology.
Later, Juice's gang return to beat up Dodger some more and knock down the garbage pail in the process. After the bullies leave Dodger for dead in the sewers, he is rescued by the just-freed Garbage Pail Kids. After Captain Manzini finds out that the kids have been released from the garbage pail, Dodger is introduced to them. Manzini proceeds to find a way to get the Garbage Pail Kids back into the garbage pail while Dodger befriends them.
The Garbage Pail Kids eventually learn that Dodger has a crush on Tangerine, and they help by making him clothes to impress her because she is interested in fashion. In addition, the Garbage Pail Kids also want to find their missing friends, the other Garbage Pail Kids, who are believed to be imprisoned at the State Home for the Ugly, a prison that incarcerates and executes people just for looking abnormal.
Tangerine later learns about the seven Garbage Pail Kids and gives their location to Juice. Juice and his gang proceed to capture the Garbage Pail Kids and turn them in to the State Home for the Ugly. There, the kids are put in a cell labeled "Too Gross". Other prisoners are shown to include Santa Claus(imprisoned for being too fat), Gandhi(imprisoned for being too bald), Abraham Lincoln(imprisoned for being too tall), a clown(imprisoned for being too silly), and a crossdressing man(imprisoned for being too weird).
Dodger and Captain Manzini eventually rescue the seven Garbage Pail Kids and free them from the State Home for the Ugly, as well as everyone else incarcerated there. Unfortunately, they were too late to save the other Garbage Pail Kids the seven main kids were looking for: They had already been executed(or so it appeared). After giving Juice and his gang their comeuppance, the Garbage Pail Kids reluctantly let Captain Manzini put them back in the garbage pail, only to trick him so that they can get away. In the end, Captain Manzini lightens up and decides to let the Garbage Pail Kids go free.
The film did not do very well in theaters. Many critics even declared it to be one of the worst movies ever made. Despite this, the film has managed to maintain a cult following and a small fanbase.
The film ended with many plotholes that were meant to be explained in a proposed live-action Garbage Pail Kids television series, but this never materialized.