* Despite the English dub using the ''kanzenban'' footage, the opening of the original North American DVD release uses a hand-drawn shot of the big doors opening.
* The title of this movie is also used in [https://www.youtube.com/watch?v=P-zJOntZRHo Mewtwo's trailer] for [[Super Smash Bros. for Nintendo 3DS/Wii U]].
* The [https://www.youtube.com/watch?v=b70GRNYnacI first trailer]
for Mewtwo Strikes Back showed several prominent scenes that never appear in the final cut of the film. Most notably were scenes of Ash fleeing an explosion, a woman who looks like Misty and a younger character, and Team Rocket standing on a warship.
** Largely because of the resemblance, as well as Pikachu being present, it was initially speculated that the woman in the trailer was an adult Misty. However, this was confirmed to be false by Kunihiko Yuyama during the 2019 Pokémon Anime Expo premiere of [[M22|the
film's remake]] , that the woman was designed specifically for the trailer, and had absolutely no relation to the main cast of the movie or the main anime in any way.