When Disney acquired the distribution rights to this film, the studio found it too violent. The filmmakers responded by adding cartoon sound effects to lessen the violence. The American version of the film also cut numerous parts of scenes, most likely to secure a PG rating.
Michael Treanor and Max Elliott Slade were like brothers. In fact, Michael Treanor quotes, "Once Max got me into a headlock while I was memorizing my lines. I got him pinned pretty quick. It was funny watching him trying to get out of my grip. He wouldn't give up 'til 10 minutes later. The kid needs to learn to give up!"
The international version of the movie featuring the scenes removed from the American version has never been released on home video in the United States, although it has aired on the WAM! movie network.
The trivia item below may give away important plot points.
Despite the fact that the 3 Ninjas (Rocky, Colt, and Tum Tum) are the main protagonists in all four films, they never face the main villain in any of the series entries. In this film and 3 Ninjas Kick Back, Grandpa is the one who faces and defeats Snyder and Koga (although the latter renounces his evil ways in the end); in 3 Ninjas Knuckle Up, the villain Jack Harding gets punched in the face by Charlie; And finally in 3 Ninjas High Noon at Mega Mountain, no one faces off against Medusa, but she is rather forced to surrender to the FBI.