Like its preceding single, "Prove It" was a staple of Television's early live shows, often as a set closer. The lyrics, reflecting upon a detective story, echo the movie The Long Goodbye which came out a few years before Marquee Moon.
In the United Kingdom, "Prove It" was released as a single on July 22, 1977. The first 15,000 copies were pressed on light green vinyl, and the next 15,000 were in dark green vinyl. The single charted for four weeks and peaked at number 25 on the UK Singles Chart on July 30, 1977.