Harold Lee and Kumar Patel are two stoners who end up getting the munchies. What they crave the most after seeing a TV advertisement, is a trip to White Castle. So from here, follows a journey for the burgers they require. On their way they will encounter many obstacles including a raccoon, a racist officer, and a horny Neil Patrick Harris.

The morning they return from their White Castle road trip, Harold and Kumar decide to go to Amsterdam because Harold doesn't want to wait ten days to see Maria again. On the plane, Kumar lights up his new bong, the air marshals think it's a bomb, and Harold and Kumar are arrested as terrorists and sent to Guantanamo Bay. Ordered to fellate a guard, they manage to escape, make their way to Florida, and head for Texas to find Kumar's ex-girlfriend's fiancé, the well-connected Colton, and get him to intercede with Washington on their behalf. Kumar still has a thing for Vanessa, the feds are in hot pursuit, and the legal weed of Amsterdam seems a long way away.