The last film to be directed by South Korean filmmaker Sang-ok Shin (credited under the name Simon Sheen). In 1978, Shin and his wife Choi Eun-hee were kidnapped by the North Korean government and forced to make propaganda movies for 8 years. The couple managed to escape during a Vienna Film Festival in 1986 and were granted political asylum by the American embassy.
This is the only film in the "3 Ninjas" franchise to be rated PG-13.
Out of the entire 3 Ninjas quadrilogy, this is the only film which doesn't feature the boys' parents Jessica and Sam Douglas.
Filmed in 1992.