Trivia: When Harry is being run all over town by Scorpio, he passes a wall which bears the graffiti "Kyle", the name of Clint Eastwood's son.
Trivia: In the scene where Alex approaches the two girls at the record stand you can see the original score for 2001: A Space Odyssey, also directed by Stanley Kubrick.
Suggested correction: The album shown in the picture is NOT, as is commonly believed, the soundtrack of 2001, but rather a compilation of movie theme music that includes the main theme of 2001. However, the ACTUAL soundtrack of 2001 is still visible in the scene, just a little earlier: When Alex finishes flipping through a magazine and tosses it down on a counter, one of the records in that shot is the 2001 soundtrack.
Trivia: John "Biffo" Bindon (played Sid Fletcher) had numerous roles during the '60s-'70s as the gangster-type. In real-life he had a violent temper, provoked pub fights and ran a protection racket. It's been suggested that he was known to associate with organised crime leaders the Kray twins and the Richardson Gang, but the extent of his involvement in the English underworld has never really been proven. In 1968 he was awarded the Queen's Award for Bravery (a police bravery medal) for rescuing a drowning man by diving off the Putney Bridge into the River Thames. Some have said that it was Bindon who pushed the man off the bridge but was forced to rescue him when a policeman showed up. By 1971 Bindon went into organising security, which had unfortunate results when hired to be security co-ordinator for Led Zeppelin, during their U.S. concert tour. Then in 1978, Bindon was in a knife fight with London gangster John Darke, which resulted in Darke's death, and by 1979 was on trial where the prosecution claimed it was a contract killing. Defence argued that Darke's death was in self defence (there were allegations that while awaiting trial Bindon bragged to a cellmate that he was a hitman). Though Bindon was acquitted of Darke's murder, his reputation was badly damaged and he became reclusive in the 1980s, before his death in October '93, of AIDS.
Trivia: Eddie Egan, the real police detective who inspired the character Popeye Doyle, plays Doyle's superior in the movie.
Trivia: The British Board of Film Censors (BBFC) banned this film from being released on video/DVD from 1984 to 2002 due to its graphic violence and two brutal rapes.
Trivia: Christopher Lee's only western.