Guy Madison's voice was dubbed by another actor in the English language version.
According to the biography of Heinz Erhardt the movie was supposed to be shot in Mexico, which he was really excited for. When he got the necessary vaccinations, they caused him to be bedridden with high fever for 9 full days. Just as he felt better, the producers informed him that the Mexico shoot was canceled and all his scenes were to be shot in Germany.
Georg Marischka wanted to cast Buster Keaton as Don Parmesan and actually talked to the legendary American actor on the phone, but an agreement couldn't be reached, "thankfully", as Marischka remarked later, referring to Keaton's sudden passing during the shooting of the film.