According to director Paul Mazursky's autobiography, Judith Malina was originally cast as the dictator's mother. But there was a mix-up, Malina was unavailable, and the production only had the Rio opera house available for three days. They tried in vain for Zoe Caldwell, and considered a few Brazilian actresses. Mazursky ended up playing the part himself, in drag.
During a scene where Jack has to address the crowd as the Paradorian President, he ad-libs his lines and uses the text for the song "The Impossible Dream" from 'Man of La Mancha'. Only Roberto catches on, a reference to Raul Julia's leading role (Don Quixote) in the Broadway version of 'Man of La Mancha'.
Ralph, the Jonathan Winters' character, tells a long story concerning an English pirate who founded the country of Parador, to explain why Alphonse Simms has an Anglo-Saxon surname. The real reason is that the film was shot in Brazil, and director Paul Mazursky needed a shot of a crowd of Brazilian extras chanting the dictator's name. When the crowd is calling out "Simms! Simms!", they are actually chanting "Sim! Sim!". "Sim" is "yes" in Portuguese, the language of Brazil.
The previous Paradorian National Anthem, "O Parador" is sung to the tune of "O Christmas Tree." In some Latin American countries, the Knights of Columbus Anthem is sung to the tune of "O Christmas Tree."
Sammy Davis Jr.'s rendition of Parador's national anthem is sung against the music for the song "Besame Mucho."
John C. Broderick: The movie's unit production manager as the director of a film crew shooting in Parador.