- Directors: Steve Barron
- Producers: Simon Fields, Kim Dawson, David Chan, Co Producer, Graham Cottle, Executive Producer, Raymond Chow
- Writers: Comic Book, Kevin Eastman, Peter Laird, Story, Bobby Herbeck, Screenplay, Todd W Langen, Bobby Herbeck
- Genres: Action, Comedy, Crime, Drama, Family, Sci-Fi
- Actors: Judith Hoag, Elias Koteas
The film begins April O’Neil, an investigative reporter at Channel 3 Eyewitness News, is researching a story on a recent, immense crime wave in New York City. She is later rescued by the Teenage Mutant Ninja Turtles from a group of street thieves. As the Turtles are celebrating their victory, an ex-hockey player called Casey Jones, having become a vigilante so as to combat the crime wave, is shown beating two thieves with his sports equipment and arguing with the Teenage Mutant Ninja Turtle Raphael over the proper way to punish criminals. The crime wave is traced by April to the Foot Clan; when she makes them uncomfortable, the Foot Ninjas attack her and knock her unconscious, whereupon Raphael rescues her – not noticing that one Foot soldier follows him through the sewer system.
As the Turtles escort April back to her apartment, where they remain for some hours, the Foot raid the Turtles’ lair and kidnap Splinter. They carry him back to their headquarters, where their master Shredder is forming an army of corrupted, ninja-trained teenagers to build himself an empire of crime. One of those teenagers is Danny Pennington, the son of April’s boss; having seen the Turtles at her apartment, he tells Shredder where to find them. The Foot therefore launch a surprise attack on April’s apartment. Caught off-guard and outnumbered, April, the Turtles, and Casey (who had intervened when he saw Raphael in danger) are forced to escape to April’s childhood home in a rural farmstead. Raphael is rendered unconscious during the battle and does not wake from his coma for several days, during which his brothers and their friends use diverse methods to recover from their losses.
The trainees of the Foot Clan confess all of their involvement to the New York Police Department, while April asks Casey for a kiss, which he gives wholeheartedly. The film concludes with Partners In Kryme’s track “Turtle Power” and the Turtles celebrating their victory over the Foot Clan. Splinter, to summarize their emotions, contributes the word “Cowabunga” (a favorite slogan in later films), to which he proclaims “I made a funny! Ha, ha, ha, ha, ha!”.