The song is used to frame the scenes in the film where Connor MacLeod must endure his beloved wife Heather MacLeod growing old and dying while he, as an Immortal, remains forever young. The song's title is taken from a line in another movie scored by Brian May and Queen, Flash Gordon (the line can be heard on "Battle Theme" from the Flash Gordon soundtrack album) and is based on May's personal troubles (the death of May's father and failing first marriage).
In the film, Freddie Mercury provides all the main vocals, while May sings lead vocals on the first verse on the album version, before Mercury takes over for most of the rest of the song, with May singing "But touch my tears with your lips" during Mercury's verse and then the final line of the song, "Who waits forever anyway?". An instrumental version of the song, titled "Forever", was included as a bonus track on the CD version of the album. This instrumental featured only a piano, with keyboard accompaniment during the chorus sections. The piano track was recorded solely by May. Queen was backed up by an orchestra, with orchestrations by the co-composer of the film's score, Michael Kamen. Since its release, the song has been covered by a number of artists.