Many of the actors as well as Will Ferrell are well versed in the art of improvisation and would sometimes do up to 20 different versions of reaction lines trying out the first thing that popped into their heads.
Adam McKay has said that in the first draft of the script, the story was about a planeload of news anchors who crash in the mountains and discover that the plane which they collided was carrying monkeys and martial arts equipment, leading to a battle between cannibalistic newsmen and star-throwing monkeys.
Champ's line "I will take your mother, Dorothy Mantooth, out for a nice seafood dinner and never call her again" is a reference to the comic book series 'Dan Dare, Pilot of the Future', where Dare's nemesis, the Mekon, makes an identical threat against Dorothy Dare, Dan's mother.
This film had been pitched to DreamWorks nearly 20 times before, following the successes of Old School (2003) and Elf (2003). DreamWorks had little faith in the film, doubting Will Ferrell and Adam McKay were able to pull off an entire film based on news anchors. Despite the doubts the film would bomb, it grossed $84 million domestically and the director had so much extra footage they were able to make a second film out of it.
Director Adam McKay was supposed to have a small cameo as a network producer named Aaron Zimmerman who acted much like Robert Evans but the idea was cut midway through production. The idea was reprised however in the feature introduction commentary to Wake Up, Ron Burgundy: The Lost Movie (2004).
Before the news team brawl there is a graffiti tag on the wall visible (as Vince Vaughn's (Wes Mantooth) news team ride their bikes into the alley) that reads "Channel 9" - the name of Mantooth's news team.
A good portion of scenes from the trailers are completely omitted from the film's final cut. These scenes include Burgundy taking a bullet for Veronica and a later shot of him and her emerging from a TV van to a cheering crowd with Burgundy visibly showing a bandaged wound. The line where Ron asks Garth about his divorce while at a party is also missing. Other shots cut include Ron walking into a filing cabinet and falling over, alternate dialog when Ron asks Veronica what her dream is, Veronica and Ron tackling each other on the conference room table, collapsing (with Ron shouting "Let's make a baby!"), Ron admiring his own billboard, Ed Harken asking what a "lead" is, sitting by a poolside, standing by the side of the road with a long beard and guitar on his back trying to hitchhike, and others.
In the night club, Ron plays jazz flute in the style of Ian Anderson, lead singer and flautist of Jethro Tull. Ron blurts out "Hey Aqualung!" at the end of the song, a lyric from the Jethro Tull song "Aqualung", the title track of their 1971 album. In addition, the riff that he plays on the flute just before he does so is the main riff of the same song. Indeed, the scene is rife with Tull references, as the pose Ron strikes at the end of the song is also a clear imitation of the band's logo of a flautist turned sideways with one leg up. Ironically, "Aqualung" does not feature any flute.
When the in-studio monitor shows the rolling credits during Ron and Veronica's banter, two of the credited writers listed are "Jon Hamm" and "Adam Scott", both of whom are close friends of "Paul Rudd".