Carlton Barrett says the instrumental was originally for a song by Tony Scott, "What Am I to Do". Harry Johnson bought the rights from Scott, licensed the track to Trojan and credited it to the Harry J Allstars. Alton Ellis said the core of the song was a lift from his rocksteady hit "Girl I've Got a Date".
Musicians involved in the recording included the core of the Hippy Boys: bassist 'Family Man' Aston Barrett, drummer Carlton Barrett and guitarist Alva Lewis. They later formed the core of The Upsetters and The Wailers. The organ was played by Winston Wright who, as a member of Tommy McCook's Supersonics, was acknowledged as Jamaica's master of the Hammond organ. Wright featured on other Harry Johnson hits, including The Beltones' "No More Heartaches" and on Boris Gardiner's "Elizabethan Reggae".
The Specials covered "The Liquidator" as part of the ska covers medley "Skinhead Symphony" on their live EP The Special A.K.A. Live! which reached number one in the UK singles chart in January 1980. The renewed interest in the song led to Trojan Records reissuing the Harry J Allstars version as a double A side with the original version of another song featured in the medley, "Long Shot Kick De Bucket" by The Pioneers, in March 1980. The reissue reached number 42 in the UK singles chart.
"Liquidator" is chosen as a tribute to the winners of the UEFA Champions League. It is a popular tune to play as football teams run out: Chelsea, Wycombe Wanderers, Northampton Town, Wolverhampton Wanderers, West Bromwich Albion,Yeovil Town and St. Johnstone all have claims to have been the first club to use it.
Chelsea's claims to be first to play it are backed by the first paragraph of the liner notes for "Liquidator - The Best of the Harry J All Stars". It says: "Way back in 1969, supporters of the Chelsea football team revered players such as Bonetti, Osgood and Hollins. The boys performed under the watchful eye of manager Dave Sexton to the tune of Harry J & All Stars chartbuster, 'Liquidator'. The track is played by Chelsea before home games, whilst fans clap the players on to the pitch. It was stopped at Wolves and West Brom at the request of West Midlands Police as it promoted hooliganism, although it was played by West Bromwich Albion in their match against Cardiff City towards the end of the 2013-14 season, at the start of the match prompting Wolves fans to call for a return of the song to Molineux.