The song was first played live at Mont De Marsan (Landes - France), in August 1977 and recorded the same year in the band's October and November sessions at CBS Studios. Following an argument at the end of the band's Get Out of Control Tour, Paul Simonon and Mick Jones were not on speaking terms, leaving Joe Strummer as a middle-man, relaying instructions and insults from one to the other. In December, producer Mickey Foote (Joe Strummer's old sound-man from the 101'ers and producer of The Clash and "White Riot") increased the speed of the tape for the finished master of the song after manager Bernie Rhodes decided the song sounded "a bit flat." This technique, known as "varispeeding," rendered the song one semitone higher in pitch. Strummer and Jones were in Jamaica at the time. When they heard the finished result, Foote was sacked. With the exception of the 2000 re-issue of the US version of The Clash, the original version of the song (at the proper speed) has been used on every re-release since.
The Clash's first overt attempt at self-mythology, "Clash City Rockers" is, by and large, a song about positivity and moving forward, and revisits themes common in Clash songs of the era, specifically dead-end employment and having a purpose in life. The middle part of the song is based on an old nursery rhyme, "Oranges and Lemons", and namechecks The Move, The Groove, David Bowie, Gary Glitter and Prince Far-I; the irony of the line "when I am fitter say the bells of Gary Glitter" following his scandal was not lost on Mick Jones, who joked about it in December 2003 of Uncut magazine:
"The Gary Glitter lyric? Yeah, that was before the internet. [grins]"
The main riff is very reminiscent to The Who's debut single, "I Can't Explain"'s main riff, and sounds like it has been expanded by The Clash. This riff was reworked by the band again for "Guns on the Roof" on their second album Give 'Em Enough Rope.