Continuity: In the scene with the diarrhea twins, when Harold and Kumar go into the middle stall, you can see that all of the doors are closed. When the twins are standing at the mirror in the bathroom, you can see that the door, in the mirror, behind the twin in pink is open.

Continuity: In the shot when Harold and Kumar stop to take a pee and then leave Harold gets bitten by a raccoon and in one shot you see Harold's blood stain on his jacket in the next shot its gone the shot after that one you see it and so forth it happens for about a few shots until the car comes to a stop.

Continuity: When Harold and Kumar go into the women's bathroom at Princeton they run into the middle stall to hide from the girls. You can see the legs of the girl in the left stall before she even goes into the stall.

Continuity: In the scene where Kumar is at his interview for med school, when the dean of admissions spills his coffee on himself he puts the coffee cup back on the table but in-between shots the handle of the cup changes directions.

Deliberate "mistake": When Harold and Kumar go to the Burger Shack drivethru, the employee goes nuts shouting about burning the place down. As he pulls over the breadrack his hat falls of his head. We then see him make his way back over toward the window and then fall. As he gets back up he is again wearing his hat which should still be several feet behind him.

Revealing: After they almost drive the Xtreme truck off of the cliff, Kumar gives a speech on their ancestors. He appears to be standing too far in front of the vehicle, which is partially over the cliff. In some shots in the same scene we see him standing on a short outcropping, but the angle of him to the vehicle doesn't match with the earlier shots.

Revealing: During the scene where the gang are beating up the two guys in Newark, observe the black guy in beige pants: he is making kicking motions but not actually connecting with anything. He is about two feet away from the guy on the floor.

Revealing: During the hanggliding scene we see from the close up shot that Harold and Kumar are both on the hand glider. However, from the wider aerial shots there is only one person in the glider.

Continuity: When Harold and Kumar almost crash into Goldstein and Rosenberg we see Goldstein's car stop a short distance behind Harold's. Then in the wide shot the car is now much further down the road.

Continuity: The bloody scar on Harold's forehead changes in different scenes.

Revealing: In shots of the drive-through guy at the the Burger Shack, it can be seen that the restaurant has no back wall.

Continuity: When Kumar is interviewing at Princeton, the cup is not only changing directions, but sometimes is missing and at one point it is sitting slanted on top of a pen.

Continuity: After H and K almost hit Goldstein, they talk after realizing who's who. Kumar lowers his window and says "Goldstein?" When they show that shot the car that Kumar is in is fairly clean, but in the next shot of him opening the door, it's a lot dirtier.

Factual error: When they stop at the gas station to ask for directions, you can see a Country Style donuts sign on the outside wall. Country Style is a Canadian brand.

Factual error: Near the end of the movie where H&K are stealing the skateboarder's truck, there is a Shoppers Drug Mart in the background. Shoppers Drug Mart stores are only located in Canada, not New Jersey.

Continuity: When Harold is given the paperwork to do by his boss in the beginning of the movie, his boss is giving him an "okay" sign and a "number one" sign with his right hand. The last shot before his boss leaves, he put down his left hand, which he was not using to make the signals.

Continuity: As we see Harold and Kumar in the car we see a close up shot of Harold on his laptop. We also see a USB wire in the side USB port to which is attached a small light set off to the left of the screen. In one of the wide shots this light can be seen, but in all the others it has disappeared.

Continuity: When Harold and Kumar almost get in a car accident, Kumar rolls down his window all the way down when talking to Goldstein, but the next shot of Kumar opening the driver side door, the window is now only half down instead of all the way.

Revealing: When Kumar is clipping his pubes in Harold's mirror, when they go to a close up of Kumar's face and torso when he's speaking, you can see the blue shorts he's wearing for the shot. When Harold entered the room we can see Kumar from behind nude facing the mirror.

Continuity: Harold's Toyota Camry changes between shots a few different times in the movie. In the beginning and for the majority of the movie, the Camry is one of the more expensive trim levels with alloy rims. During some of the shots, it switches back and forth from this to a base model Camry with wheel covers. One of the times this happens is when they are wrestling with the raccoon.