Gary Oldman wore Sid's real chain necklace in the movie. When doing his research, Sid's mom gave him the necklace to wear during filming.

Gary Oldman lived on a diet of steamed fish and melon to lose enough weight to play the emaciated, heroin-addicted Sid, and was hospitalized when he went too far and became malnourished.

According to Gary Oldman, he disliked the script, and dislikes punk music. But he accepted the role because of the salary, which was 35,000 pounds.

Chloe Webb and Gary Oldman improvised their dialogue in the scene leading up to Spungen's death. They created their dialogue from archival interviews and other materials available to them.

In a later interview, John Lydon was asked the question, "Did the movie get anything right?" to which he replied: "Maybe the name Sid."

Sid's mother Anne Beverly initially tried to prevent the movie from being made, but after meeting with Alex Cox, she decided to help the production. Gary Oldman visited her while researching the role, and described her as "very warm and open and helpful."

Tim Roth turned down the role of Johnny Rotten (John Lydon), as he felt the film depicted history that was too recent.

The real Johnny Rotten (John Lydon) dismissed this film as "mere fantasy... the Peter Pan version."

Courtney Love auditioned for the role of Nancy Spungen, but was cast as Nancy's friend Gretchen instead. Alex Cox was impressed by Love's audition and considered casting her as Nancy. But the film's investors insisted on an experienced actress for the role. By way of an apology, Alex Cox then cast Courtney Love as one of the main characters in his next movie Straight to Hell (1987).

To prepare for the scene where Nancy smashes a phone booth, the crew had replaced a few panes of glass with fake glass. But Chloe Webb was so caught up in the moment that she broke several of the real glass panes, too, and was lucky she didn't get cut up.

Gary Oldman later told Playboy: "I don't like myself in the movie, no. Frankly, I didn't want to make it in the first place ... I don't think I played Sid Vicious very well".

The film was originally called Love Kills. Near the end of post-production, one of the companies financing the film received a letter from someone claiming to own the title and threatening legal action if they used it. Alex Cox reluctantly changed it at the lawyers' insistence. He would later describe the title Sid and Nancy as "bland," but he liked what it was called on video in Mexico: Two Lives Destroyed by Drugs.

The scene where Sid and Nancy shoot cap guns at each other was filmed across the street from New Scotland Yard (i.e., London police HQ), and all anyone down below could see was that two people were waving guns around on a rooftop. Black-clad snipers soon appeared on an adjoining roof, joined by a police helicopter, and production stopped until Alex Cox and the actors could sort everything out with the constabulary.

In his 2007 autobiography, Slash revealed that the casting director hired all five members of Guns N' Roses as extras for a club scene, having coincidentally scouted them in different locations without their knowledge. He said "all of us showed up to the first day of casting, like 'Hey...what are you doing here!'" However, Slash was the only one in the group to stay the entire three day shoot.

Alex Cox and cinematographer Roger Deakins wanted to shoot the film in stark black-and-white, fitting the bleak tone. Unsurprisingly, the people financing the movie nixed that idea as too artsy and potentially off-putting to audiences. Instead, Deakins shot in color but designed it so the images become increasingly monochromatic as the film goes on, so that by the end the film is practically gray.

Though not mentioned in the film, Sid's one and only solo album, which we hear references to in the movie, was titled "Sid Sings". Also not mentioned is the actual name of the band that we see Sid put together while in New York City. They were called "Vicious White Kids", and though they never officially released an album, a bootleg of one of the very few gigs they actually did play can be found to this day, though the recording is of dubious quality.

Nancy Spungen's parents, Frank and Deborah Spungen, wanted nothing to do with the production and had no interest in seeing a movie depicting their daughter's death.

Director Alex Cox's second choice for the role of Sid Vicious was Daniel Day-Lewis.

The real Sid Vicious was known for wearing a red t-shirt with a Nazi swastika symbol. For the purposes of the film, the t-shirt bares a Communist symbol.

The line "He washed his feet too much" from Johnny Rotten was based on the fact that original Sex Pistols bass player Glen Matlock would continuously wash himself on tour whenever they arrived at a hotel. This supposedly being one of the reasons that he was replaced by Vicious. It is also mentioned in The Sex Pistols documentary The Filth and the Fury (2000).

One of the film's trailers was refused certification by the British Board of Film Classification.

Neither Sex Pistols' original bassist Glen Matlock nor guitarist Steve Jones have been as outspoken about the movie as John Lydon, although Lydon claimed that drummer Paul Cook was more upset over the movie than he was.

According to Alex Cox, both he and Andrew Schofield did meet with John Lydon before the filming. According to Cox, Lydon noticed that Schofield was, like Cox, a Liverpudlian, rather than a Londoner like Lydon, and encouraged him to play the part as a Scouser rather than a Londoner. Cox took this as a sign that both of them agreed that it would be better to portray a more fictionalized version of the characters rather than a cold re-telling of facts. Cox claims that Lydon drank heavily at these meetings, which may explain why Lydon did not recall them. Cox stated in a book that contrary to Lydon's claims, his meeting with Schofield was not after the film's completion, but rather before Schofield had even been given the part. He was offered the part the next day.

Joe Strummer claimed to have met with Alex Cox for the first time after the completion of the film, at a wrap party, but this is not entirely accurate. The wrap party was actually the conclusion of the London phase of the filming, which was followed by filming in Los Angeles and New York City, performed by a largely different crew. The pair's meeting involved discussion over soundtrack work for the film, not the film's script.

The official soundtrack contains no songs sung by either Sex Pistols or Sid Vicious. Much of the actual film's soundtrack (as opposed to soundtrack album) was composed by Joe Strummer, who was contractually limited to contribute only two songs. Nevertheless, he continued to contribute more (unpaid) work because of his interest in the project and composing for film in general. This additional material was credited to fictitious bands in the credits, so as to keep Strummer's label, Epic Records, from knowing what he had done. Another large portion of the music was composed by The Pogues.

Extras for the concert scenes were chosen based on appearance, which meant a lot of actual punks were present. And something that punks did back in the day was spit on the bands they liked. The actors playing Sex Pistols and other bands complained about the constant shower of saliva, but Alex Cox, reluctant to dampen the extras' enthusiasm and commitment to authenticity, wouldn't ask them to stop.

Alex Cox's attitude toward his subjects was indeed unapologetically negative, writing that "Sid had sold out, contributed nothing of value, died an idiot." Cox went on to say that one of the reasons he was attracted to the project was that he was afraid that if someone else made it, it would portray its subjects as "real exemplars of Punk like I am; rather than sold-out traitors to it." He acknowledged that John Lydon's hatred of the movie was "understandable, given that it was based on incidents from his life and centered around one of his friends."

The film premiered in the Directors' Fortnight section of the 1986 Cannes Film Festival, in a lavish, packed auditorium. According to Alex Cox, some or all members of Duran Duran were in the audience, and when Gary Oldman first appeared on the screen, one of them yelled, "Johnny Thunders!" (referring to another punk musician who'd been with New York Dolls). Joe Strummer stood and yelled, "Shut the f*** up!" Duly chastened by their elders, they shut up.

Andrew Schofield's portrayal of John Lydon was heavily criticised for being inaccurate. Paul Simonon of The Clash was annoyed that Lydon was portrayed "like some sort of fat, bean-slurping idiot...That pissed me off, making him look like an idiot".

Alex Cox offered Gary Oldman the part of Sid Vicious after seeing him play the lead role of Scopey in a 1984 production of Edward Bond's The Pope's Wedding.

The music video for Joe Strummer's "Love Kills," is sort of a fantasy sequel to the film, where a heavily disguised Sid Vicious (played again by Gary Oldman) faked his death and fled to Mexico, where he runs afoul of the local constabulary.

In 1980, Alex Cox wrote a screenplay about an American detective hired to find a rich girl who ran off with an English bassist. It was a fictional story inspired by Sid Vicious and Nancy Spungen, adorned with references to current political events in England that, in Cox's view, "guaranteed it would never be made into a film." He put it away and did other things-like Repo Man (1984).

The first cut of this film was three and a half hours long.

In real life, Gary Oldman was a close friend of pop singer, writer and actor David Bowie.

The title was chosen as an homage to Romeo and Juliet.

Although his performance in Sid and Nancy (1986) put Gary Oldman on the map, he cannot bear to watch it to this day. He hated the subject matter and took the job only for the money. "If it comes on TV and I'm channel surfing and I see a second of it, I just want to throw the television out the window", he remarked in a 2016 interview. And in 2018 he said, "I just don't think I was very good in it". Oldman has praised the film's cinematography by Roger Deakins, however.

This film is part of the Criterion Collection, spine #20.

The stabbing scene is fictionalized and based only on conjecture. Alex Cox told the NME: "We wanted to make the film not just about Sid Vicious and punk rock, but as an anti-drugs statement, to show the degradation caused to various people is not at all glamorous."