There's a nude scene, where Ina Balin leaves the bath-tub, as Elvis's character appears in her room. This scene is rarely seen, and is generally not in the edits of the film that have been televised or on video/DVD.
The film's title, "Charro", which refers to the nickname of Elvis's character Jess Wade, loosely translates from Spanish to English as "singer". Specifically, "Charro" refers to the lead singer of a mariachi band. Although it's a fitting name for an actor known as a singer, Elvis ironically does no singing in the movie.
This movie was part of a deal that 'Colonel Tom Parker' signed for Elvis Presley with NBC and National General. Elvis was paid a large sum for doing both the well-known NBC TV Special (now called The '68 Comeback special) and this picture for National General Pictures. The TV special was shot at the end of June 1968 (and aired in December) and the film was shot in July and August 1968 (and was released early 1969). The TV show was supposed to be a Christmas Special with Xmas songs only but turned to be a rock 'n' roll revival show while the movie, on the contrary, was supposed to be much more violent.
The songs were recorded in November 1968 at the Goldwyn Studios. "Charro", the title song appeared on the B-side of Elvis's single "Memories" (1969). A second song, "Let's forget about the Stars", written by A.L. Owens, was recorded for but not used in the film. It appeared, among others, on the compilation album "Let's be Friends" (1970).
Promotions for this film included twenty-five Southwestern cities which held "Charro Girl" contests, with finalists appearing in Dallas and Austin. In Austin, "Charro! Day" was hosted by the then Governor Preston Smith. Likewise, the governors of Oklahoma and Louisiana declared "Charro! Day" in honor of previews in their states. A number of actors from the film traveled to appearances at these sneak previews.