The footage of Elvis Presley singing "Love Me Tender" at the end was shot after preview audiences reacted badly to his character's fate. This new footage created a continuity error, as Elvis had dyed his hair black by the time of the additional shooting, whilst in the movie his hair color was closer to blonde.
Elvis Presley is credited as co-writer of the film's four songs, but in fact had little to do with writing them; it was just for purposes of royalties. Elvis revealed at a 1968 press conference, when asked about his " lack of songwriting in general", that he did contribute one line of lyrics to the title song, "Love Me Tender".
Extra scenes and lines were added for Elvis Presley's character, which was originally supposed to be a minor role before he got the part.
Although originally slated to be an inexpensive "B" picture, it was upgraded to an "A" feature with a $1-million budget after Elvis Presley was signed to star.
Possibly the first American film to use a "squib hit" on an actor (using an explosive under clothing with a blood pack to simulate a bullet hit).