Elvis Presley later said about the film: "I wasn't exactly a James Bond in this movie. But then, no one ever asked Sean Connery to sing a song while dodging bullets".
Annette Day made in the movie, her screen debut - so far, it's her only role too. Producer Judd Bernard found her while he was with his wife shopping in London and entered an antique shop. Shop was owned by her parents. Judd Bernard asked her to have a lunch with him and talk about a part in a movie. Bernard, Day and Lee Marvin had lunch together in a hotel. Later Bernard went back to Hollywood, and soon Day got a message from him telling to travel to Hollywood and make a screen test. She got a role in the movie.
Mary Hughes's last film.
Although the film is set in Europe too, Elvis Presley never filmed outside Culver City, California. Second unit filmed in Belgium with body stunts; Joe Clauwers for Elvis Presley and Paula Geerts for Annette Day.
First film produced by Irwin Winkler.
Lines "biccies" and "super-duper" was added on the screenplay after director Norman Taurog heard Annette Day saying those on the set.
One lucky Elvis Presley fan bought a jacket as a gift to Elvis. Elvis told her to watch the movie carefully when it came out. The film came out and she saw that the jacket was in the suitcase which belongs to Elvis' character on film.
Only movie Annette Day made.
Red jacket wore by Elvis Presley on the movie was sold in an auction in 1996. Highest bid was $11,500.