This is the only movie in which Elvis Presley doesn't sing. The only song is the one during the titles.
There's a nude scene where Ina Balin leaves the bathtub as Elvis' 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.
Elvis wore his hat like the western actor, Bing Russell, in Charro! After telling Kurt Russell, his son, that he was a fan and would do this if he acted in another western.
Elvis Presley was really keen on the project, as it afforded him the chance to break out of the rut of cheap musicals he had been turning out. This was his opportunity to be seen as a serious actor but he was hugely disappointed when he showed up on the first day of filming to find that the script had been completely rewritten and was a pale shadow of what he had originally signed on for. Contractually, he was obligated to fulfill the role.