It was released as a single in July 1962, a week before the release of the film.[4] The music was composed by Norrie Paramor, known for being the producer for Cliff Richard, and the lyrics written by Dick Rowe, producer and Head of A&R at Decca Records.[5]
"Once Upon a Dream" was released with the B-side "If I Lose You", written by Fury, in the UK, Ireland, Denmark, France and India.[5] However, in Australia, it was released with the B-side "You're Swell", written by Rowe, and in Germany, the B-side was "Play It Cool", written by Paramor.[6][7] These two B-sides had been included on an EP titled Play It Cool, released in May 1962.[8]