Jan Shepard's baby was offered for the role of little baby on the film.
Ursula Andress tested for the role of Lili which eventually went to Juliet Prowse. Also May Britt and Elke Sommer were considered for the role.
According to the Hal B. Wallis papers at the AMPAS Library, Michael Curtiz was originally set to direct the film. Curtiz directed Elvis Presley in King Creole, his previous picture.
According to the Hal B. Wallis papers at the AMPAS Library, Frank Gorshin tested for the role of Cookie and both Russ Tamblyn and Johnny Carson were considered but the filmmakers decided to go with an older actor who could a "breezy conniver with the girls" in order for the character to be portrayed successfully.
All of the main cast scenes were filmed in Hollywood on indoor sets, in front of process screens, and on backlots. Location and exterior shots were filmed in Germany, but they used stand-ins and were intercut with the process-screen shots.
Despite the European locale, all of Presley's scenes were filmed in Hollywood.
Princess of Denmark, Norway and Sweden, King of Thailand and other royalties visited on the studio and met Elvis Presley.
The 32nd armored was Elvis's regiment when he was in the army and in this movie.
The boat Elvis boards ("Bonn"), is now in Karlshamn, southern Sweden, and is used as a discotheque.
The number of the sky lift Tulsa and Lili ride on is 76.
The song "Pocketful Of Rainbows", seemingly a duet with Elvis and Juliet Prowse, had Prowse lip-syncing to an unknown backup singer's vocals.
The working title for this movie, "Café Europa", is also the title by which the movie is known in a number of European countries (Germany and Italy amongst others).
This would be the only movie role where Elvis would sing one of his established million selling oldies.("Blue Suede Shoes" from 1956).
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.
While Tulsa (Elvis Presley) is singing "Doin' the Best I Can", one soldier puts a coin in the jukebox and choose from the list "Blue Suede Shoes - Elvis Presley".