Frank's streaking scene was shot on a city street. As Will Ferrell remembered it, one of the storefronts was a twenty-four-hour gym with Stairmasters and treadmills in the window. "I was rehearsing in a robe, and all these people are in the gym, watching me. I asked one of the production assistants, 'Shouldn't we tell them I'm going to be naked?' Sure enough, I dropped my robe and there were shrieks of pure horror. After the first take, nobody was at the window anymore. I took that as a sign of approval."
The foul-mouthed band playing at the wedding is a real rock band called The Dan Band. They have also appeared in Starsky & Hutch (2004) and Very Bad Trip (2009), both directed by Todd Phillips.
Will Ferrell was really naked for Frank's streaking scene. He justified it by saying it showed his character falling off the wagon. "The fact that it made sense was the reason I was really into doing it, and why I was able to commit on that level", he explained to the BBC. "If it was just for the sake of doing a crazy shot, then I don't think it makes sense." Still, Ferrell needed some liquid courage, and was intimidated by the presence of Snoop Dogg.
Vince Vaughn had to keep the crowd at the Mitch-a-Palooza scene (over three hundred extras) under control by entertaining them for at least an hour.
Some of Luke Wilson's scenes (like when he arrives home) were done in one take. The crew nicknamed him "One-take Wilson".
Stuart Cornfeld: Ben Stiller's producing partner appears as the cab driver who takes Mitch to the airport.