Despite the European locale, all of Presley's scenes were filmed in Hollywood.
The Princesses of Denmark, Norway, and Sweden, the King of Thailand, and other royals visited the studio and met Elvis Presley.
The 3rd Armored Division was Elvis's division when he was in the army, as it is in this movie.
This film marked a turning point in Elvis Presley's screen persona. Up until his stint in the U.S. Army, art imitated life, with Presley typically cast as a shy, unassuming country boy. Following his release from the armed services, Presley kicked off the hayseed, emerging as a slick, articulate bon vivant. He would occasionally mix the two personas, as in Wild in the Country (1961), but for the most part, Presley would veer toward the hip side for the rest of his career. That said, Presley's inability to obscure his drawl dictated that most of his characters came from the south.
While filming on the sky lift in Rüdesheim, director of photography Loyal Griggs fell out of a tram car, plunging thirty feet to the vineyards below, but was not seriously injured.