- Lloyd supposedly drives Mary to an airport in Rhode Island, yet the surrounding mountains indicate that it is Salt Lake City Airport.
- The position of Harry's glass of cola when laughing at the diner.
- When Lloyd is urinating in the beer bottles Harry's hands switch from the beer bottles to the steering wheel.
- In the bar, Lloyd grabs the bartender with one hand but the next shot shows him grabbing him with the other hand.
- When Lloyd is waiting in the bar for Mary, he's drinking beers and there are two bottles on the bar. The barkeeper gives him another beer but still there are two bottles on the bar
- Guitarist miming "Mockingbird".
- After shooting Harry, Nicholas' gun has the slide locked back, indicating that it is empty. In the next shot the slide is forward again.
- When Lloyd and Harry get stopped for speeding, Harry rolls the window down, even though it was already opened in shots from a moment before.
- The bathroom window in Harry's toilet scene.
- When Lloyd falls off the runway, the Asian man has a smile on his face. You can see it in the glass. But when the camera's on the man's face his expression is different.
- After they are both fired, the bottle cap that Lloyd tosses on the floor moves about between shots.
- When the guys are stopped in Pennsylvania, the state trooper is wearing a badge. The Pennsylvania State Police do not wear badges on their uniforms.
- The Aspen Police Department did, in fact, drive Saab 9000s (at least while they were still in production). However, when they arrive with Bobby, he opens the rear door himself. Rear doors on police cars cannot be opened from the inside.
- When Lloyd drives Mary to the airport, he is in a car with no airbag. Afterward, we see an airbag deploy when he hits a car.
- In the airport limo scene, when Lloyd is leaving after dropping off Mary he starts the limo and puts it in reverse and drives forward, eventually hitting the car in front of him deploying the airbag.
- When Mr. Mentalino sees the note for the gas man on Harry and Lloyd's apartment, he thinks they meant it for him, exclaiming, "how did they know I got gas?" Yet later Mentalino decides to hitch a ride with the two and takes no steps to disguise himself since he earlier made the assumption that Harry and Lloyd knew who he was.
- Harry and Lloyd drive over the same bridge twice on their way to Aspen.
- The ketchup and mustard on Harry's and Lloyd's shirts after eating the chilies.
- When the doves appear in Lloyd's dream sequence, we see two pairs of white sneakers from crewmembers lying on the floor behind them releasing the doves.
- In the opening sequence, the limo Lloyd is driving appears to be around 6 to 8 feet away from the girl on the sidewalk. When the camera angle changes and Lloyd talks to the girl, the limo appears to be only 2 feet away from the sidewalk.
- When Harry and Lloyd are leaving Rhode Island in the van, a hand can be seen moving the curtain behind Harry's head.
- Harry and Lloyd watch a Pacific Bell commercial in their hotel room. Pacific Bell is only available in California. In Utah or Colorado, they would be watching a US West (Qwest) commercial.
- When Harry is confronting Lloyd while they are outside with the fire near the pond, the gloves that Lloyd gives Harry jump from his right hand to the table between shots.