There definitely will be a sequel to The Hangover.
But star Zach Galifianakis is actually unsure if there should be.
In an interview with IGN, the actor said:
[Director Todd Phillips] is writing the script. But I haven't seen the script. I'm not running to do The Hangover 2. I told Todd, the last thing I want is the Police Academy chain all of the sudden, where I'm only known from… You've got to be careful with something like that. The movie's really good, why bother with a sequel? And I'm not saying that I'm not going to do it.
I'm just posing these questions. These are things I ask Todd. Obviously, the reason is executives have Bentleys to pay for. I would love, love, love to work with those guys again. The script has to be good! But I'm working with Todd on a movie we'll be shooting in about six weeks. So I'll do that first, and then we'll see how it goes.