During the production of the film, director Robert Rodriguez and actor Danny Trejo discovered they're second cousins.
The bathroom scene before the 2nd bar shootout was directed by Antonio Banderas. Robert Rodriguez said he didn't like using 2nd unit crews and Banderas asked if he could direct the scene, to which Rodriguez agreed.
Due to the film's relatively low budget, the same two stunt men were used throughout the movie.
This film cost approximately $7 million to make, 1000 times the amount of money Rodriguez spent to make El Mariachi (1992).
For most of the killings they used a gun that essentially fired fake blood at the characters instead of squibs. This unfortunately created too realistic of an effect resulting in them having to edit out much of the deaths for the censors.