Trivia

Some of the main supporting characters were dubbed by another voice actors, including Félix Fernández, Manuel de Juan & José Luis López Vázquez.

Initially, the script had been presented to the Censorship Board twice and both forbidden. Fearful that the project would not materialize, Spanish producers -of Opus Dei imposed a new wording by the censor of Father Antonio Garau Planas. Luis García Berlanga, drawing humor from the pain, seeing his misrepresented work, proposed to incorporate in the opening credits Father Garau as one of the screenwriters. Suggestion that was not well received by the aforementioned parties.

The film was censored in Spain and some parts were cut, also a whole new opening was re-shot and the final shot of the movie was also changed, all to eliminate ecclesiastical references that the censors of that time didn't like. The full version of the film could be found through other copies found in the Czech Republic, Belgium and Italy.

Just two months after the premiere of the movie, in Barcelona on March 23, 1958, Taurus Ediciones finished printing the number 47 of the "El Club de la Sonrisa"'s collection: a novel version of the film that was announced on its cover as "Los Jueves, milagro", according to the film by Luis García Berlanga".

Richard Basehart's voice is dubbed into Spanish by Francisco Arenzana. The actor recited all his dialogues in English.