The song is Presley's biggest hit, with 20 million copies sold worldwide, it is one of the best-selling singles of all time.

[8] According to The New York Times, quoting from the 1986 book Behind the Hits, "he told the idea to his music publisher, Freddy Bienstock, who was visiting him in Germany... Mr. Bienstock, who many times found songwriters for Presley, returned to his New York City office, where he found songwriters, Mr. [Aaron] Schroeder and Wally Gold, the only people in that day.

"[9] Barry White credited this song as his inspiration for changing his life and becoming a singer following his release from prison.

[10] In the promotional video for the Beatles' 1968 single "Hey Jude," the members of the band jokingly perform a few lines of the song.

"'O Sole mio" is sung by tenor Sherrill Nielsen, who was in The Imperials and later one of the collaborators of Elvis Presley.

The re-release held the record for the lowest selling number-one single in UK chart history until Orson's "No Tomorrow" in 2006.

In 2015, a new version of the song was recorded accompanied by new orchestral arrangement by the Royal Philharmonic Orchestra, and was released on their album of that year If I Can Dream.

As an A-side, Presley's former bass player's group Bill Black Combo charted with their version of "Don't Be Cruel" around the same time.

During an eight-week run at the top, Presley was held off strong competition from Shirley Bassey ("As Long As He Needs Me") and The Drifters ("Save the Last Dance for Me") before claiming the coveted Christmas number one for 1960.

Due to the single's delayed UK release, "A Mess of Blues" had already attained A-side status and peaked at No.

On 5 February 2005, the song returned to the top of the UK charts for one more week as part of a week-by-week reissue series of his former chart-toppers.

American country music singer and actor John Schneider released in 1981 a cover of the song as his first single and the title track of his debut album It's Now or Never.