(at around 9 mins) During Filemón's dream, Filemón was voiced by Ramón Langa. Langa is also the Spanish Castilian voice of Bruce Willis.
(at around 34 mins) When his medicine works on Tronchamulas, Profesor Bacterio phones to the real Francisco Ibáñez, Mortadelo and Filemón's creator. He will let him know that one of his inventions worked for the first time ever. Ibáñez is not interested in what Bacterio is saying, and claims a 20 euros debt instead.
The movie's distribution in Mexico faced some unexpected problems due to language differences in jargon. While in European Spanish the term "cachondo" often means troublemaker, in Mexico is a crude word for "horny", a sexually aroused or very sexually active person.
Janfri Topera, Mariano Venancio, Berta Ojea, Emilio Gavira, José Alias, José Manuel Moya and José Marín also appeared on the live action movie (Mortadel et Filemon (2003)).