During some of the wrestling scenes they used blow up dolls to replace some of the audience. Supposedly, they cost much less than extras and they looked real.
"Chancho" is a Spanish word for "pig".
Esqueleto is a Spanish word for "skeleton".
While filming a wrestling scene, Jack Black jumped from the ring and struck his head on a chair. This caused a gash above his right eye which needed stitches.
Was sent to theaters under the codename "Toast".
The little wrestling toy seen in the bus scene near the end is a miniature Nacho and was seen in Jared Hess's other film Napoleon Dynamite (2004). It is the toy that Napoleon ties a string to and throws out the window of the bus.
During film, Jack Black got a black eye from accidentally hitting his head on a metal chair.
The action figure at the beginning of the movie before we see the young Nacho playing outside the monastery is Nightcrawler, a mutant from the X-men comic. Nightcrawler was also a monk in a monastery and is, like Nacho, a character not entirely fit for his environment.
The film was partly inspired by Fray Tormenta ("Friar Storm"), aka Rev. Sergio Gutiérrez Benítez - a Mexican priest who became a wrestler to raise money for his parish.
The lyrics to the song that Nacho is forced to sing at the party, was completely ad-libbed by Jack Black.
The creative foodstuffs made by Nacho are are homage to 'Jared Hess'' previous film Napoleon Dynamite (2004), where plates of food introduced actors in the opening credits
The "Nachomobile" is a "customized" version of a pedal's tricycle commercialized in Mexico, which then gets an after-market upgrade by adding a scooter motorcycle without the front wheel and by adding wider tires.