The Hangover is a 2009 American comedy film directed by Todd Phillips, co-produced with Daniel Goldberg, and written by Jon Lucas and Scott Moore. It is the first installment in The Hangover trilogy. The film stars Bradley Cooper, Ed Helms, Zach Galifianakis, Heather Graham, Justin Bartha, and Jeffrey Tambor. It tells the story of three best men and the groom who take a road trip to Las Vegas for a bachelor party. They wake up the next morning to realise that not only have they lost the groom but also have no recollection.