In an interview, director John Carpenter said that they had to glue Kurt Russell's ears back because they stuck too far out.
According to John Carpenter in his DVD commentary on Les aventures de Jack Burton dans les griffes du mandarin (1986) with Kurt Russell, Carpenter got the job directing this film because the producers found out he did the music for La Nuit des masques (1978), and figured he could handle a biopic of Elvis Presley.
Kurt Russell visited Vernon Presley at Graceland during filming. Vernon, a supporter of the movie, suggested Kurt wear one of Elvis Presley's real jumpsuits. He picked the Adonis, which Elvis made and wore in 1972. On the DVD cover and in the 1970s Elvis scenes, Kurt is wearing the actual jumpsuit, not a copy.
John Carpenter: A long-haired man with a mustache smoking and standing behind someone at the blackjack table near the beginning of the film, when Elvis Presley's entourage is walking through the casino.