The comedy, starring Cooper, Ed Helms and Zach Galifianakis, was the surprise smash of 2009, raking in $459 million (£287 million) at the box office.
Writer/director Todd Phillips is already working on a second instalment - and Cooper is eager to get back on set with his pals.
He says, "Even if it's not a good script, I'd do it! When you have an experience like this with people you get along with, it's a rarity. So if someone says, 'Do you want to spend three months doing it again?' In a heartbeat!
"It's a very intimate thing you go through, shooting a movie. You find out whether you really like somebody, or you very much dislike somebody pretty fast. It's like doing a sport together."