Howard Stern, Robin Quivers, and Fred Norris were still doing their morning radio show five days a week during production on the film. Every morning, they would go immediately to the set after the show.
Mary McCormack originally did not want to accept the role of Alison because of Howard Stern's controversial reputation. She accepted the chance to audition only because she wanted to meet director Betty Thomas. When McCormack told Thomas that she was refusing the role, Thomas encouraged her to listen to Stern's radio show and meet him in person. McCormack became a fan of the show and accepted the role.
According to Howard Stern, he at first believed that he would be able to improvise throughout the movie, as he does on his radio show, and did not memorize his lines. Producer Ivan Reitman had to pull him aside and explain to him that he needed to learn his lines as scripted.
The character of Kenny 'Pig Vomit' Rushton is based on Kevin Metheny, the WNBC radio program director at the time. In real life, Howard called him 'Pig Virus', not 'Pig Vomit'. Pig Vomit was the name of the group that did Howard's opening theme song for his radio show at the time.
The film's opening "Fartman" sequence is based on Howard Stern's appearance on the 1992 MTV Video Music Awards. Stern (as Fartman) and Luke Perry (John Stamos in the film) presented the award for Best Metal/Hard Rock Video to Metallica for their "Enter Sandman" video; drummer Lars Ulrich and lead guitarist Kirk Hammett accepted the award. Perry and a female audience member managed to each grab a handful of Fartman's posterior, while Ulrich grabbed Fartman's codpiece. The other nominees for Best Metal/Hard Rock Video were "Let's Get Rocked" by Def Leppard, "Everything About You" by Ugly Kid Joe and "Right Now" by Van Halen.
The movie showing in the theater where Howard goes to view the premiere with the B-movie actress is called "Die Watching". Actress Melanie Good, who plays the B-movie actress, starred in a movie of that name in 1993 (Die Watching (1993)).
Howard Stern appears on Late Night with David Letterman (1982) wearing a T-shirt reading "On Strike Against NBC" and openly criticizes the network while Paul Giamatti plays an executive who watches this on TV in dismay. Giamatti later starred as Harvey Pekar in American Splendor (2003) which features a scene where Pekar causes a stir when he criticizes NBC on the same show while wearing a T-shirt with the same words written on it (which happened in real life).
John Stamos introduces Howard's Fartman character in the opening scene but in real life it was Luke Perry. Perry later admitted to Stern that he feared the movie would not be good and turned down the chance to play himself.
On May 23, 2001, Howard Stern said on his radio show that the scene where the Duke Of Rock goofs on him and calls him Big Bird was actually based on an incident with rock vocalist Steve Perry (of the band Journey). Stern recalled, "I walked in and he was on another guy's show . . . and he was like, 'Hey, look at this douchebag'. Remember in my movie the Duke Of Rock is goofing on me? That wasn't based on the Duke Of Rock, that was based on Steve Perry . . . Yeah, he just goofed on me. 'Hey Big Bird, what are you doing?'" In the article "Who Is Howard Stern?" in the June 14, 1990 "Rolling Stone Magazine," it's noted that Stern had described himself as looking like a cross between Big Bird and Joey Ramone.
In his final monologue, Kenny Rushton states that he is no longer working in radio and works as a manager of a shopping mall. In real life, Kevin Metheny, whom Kenny is based on, worked in radio until his death in 2014.
For the scenes that featured Howard Stern in high school, filming was done at Union High School in Union, NJ. Artie Lange, who would join "The Howard Stern Show" years later, graduated from the very same school.
Mary McCormack claimed that one of the reasons why she accepted the role, after initial reluctance because of Howard Stern's controversial reputation, was how it would affect her film career. She confided this to "Murder One" co-star Stanley Tucci over a lunch. Tucci quipped "What film career?" over her objection. McCormack decided to accept the role after Tucci advised her that she should accept it.
In 1999 the USA television network bought the rights to broadcast the film for its network television premiere. Howard Stern was initally hesitant to have the film censored, but because the network was willing to pay such a high price for the film to be shown on television, he relented and allowed the censorship. Since Stern did not want any dialogue dubbed over strong language and did not want any alternate scenes substituted for nudity and sexual content, the film's broadcast was unique as the strong profanity was simply beeped over and the nudity was pixelized. Stern also occasionally paused the film to comment on the censorship in a humorous way. This version of the film was also broadcast on VH1 as part of "Movies that Rock" in 2006.
The trivia items below may give away important plot points.
Despite being in the movie, Robin Quivers was never fired. She was instead temporarlly given time off while Howard attended speech therapy to better his voice and pronouncing his S. Once his show returned, so did Robin.
Howard's rise to being the #1 disc jockey in America celebration never took place in real life. Nor did he ever have AC/DC perform at his request. The event is a depiction of rallies or funerals for DJ's Howard and his crew would put on in any market they became number one in that particular radio market.