This song was based on "O Sole Mio" written in 1901 by G. Capurro and Edwardo di Capua. From Italian it translates to "My Sunshine". The original song was recorded by Enrico Caruso as well as Mario Lanza. Elvis admired both singers and had been influenced by them.
While in the army Elvis was impressed by a version called "There's No Tomorrow" by Tony Martin. He expressed his desire to record the song to music publishing associate Freddie Bienstock while he was visiting Elvis in Germany. Bienstock came back to the U.S. and asked Aaron Schroeder and Wally Gold to rewrite the song. With new lyrics and a new cha-cha style arrangement, it became "It's Now or Never".
With the addition of Boots Randolph on the saxaphone, the same musicians were present as were at the Nashville session in which "Stuck On You" was recorded. Take number 4 of "It's Now or Never" was shipped out on July 5, 1960 with "A Mess of Blues" on the flip side. In its 20-week run on Billboard's pop singles chart it peaked at #1 for 5 weeks. In its 7-week run on Billboard's R&B singles chart it peaked at #7. It had a 19-week run on the British pop singles chart, peaking at #1.
Among the other artists to record the song are singer/TV actor John Schneider, who had a country hit with it in the 1980s, and the group Wet, Wet, Wet, whose live version was featured in the 1994 television concert event "Elvis: The Tribute" and on its corresponding soundtrack album.
Often in live concerts in the 1970s Elvis would have tenor Sherrill Nielsen sing the Italian lyrics of "O Sole Mio" as a lead-in to Elvis singing "It's Now Or Never".