Continuity mistake: During the classroom scene, Donald Sutherland writes the word "Satan" on the board. In the first shot, the "t" in Satan in directly over the crease on the chalkboard. In the next shot, it is clearly on one side of the crease.
Continuity mistake: When Bluto is looking through the window of the girls' bedroom, the shot from behind him shows his shoulders are just above the window sill. The shots from inside the room show him to be a lot higher than this.
Continuity mistake: In the scene where Otter and Boon are hitting golf balls near the ROTC drills, Otter puts down the golf bag he is carrying and draws a club. The camera moves to the ROTC trainees, and when it comes back to the golfers, the bag is back on Otter's shoulder and there is no club out of the bag.
Continuity mistake: During the toga party, the mustard stain on Bloto's toga, disappears and reappears.
Continuity mistake: In the scene where Otter is making out with Shelly from Dickinson college, in the back of the car she is clearly shown with her bra off, and it his hanging on her right arm by one strap. When the guys come running out of the club seconds later to make their escape, Shelly is shown jumping out of the car and diving through the window of the car parked next to it, but her bra is now on and hooked as if it hadn't been removed yet.
Continuity mistake: Before the hearing, Katy and Boone are talking at the bottom (half) of a stairwell when Otter comes down with a briefcase in his right hand and he puts his left hand on Boone's shoulder. In the next shot the briefcase is now in his left hand with his right hand on Boone.
Continuity mistake: In the classroom scene, Donald Sutherland takes a bite of the apple and a split second later in the next shot, he has nothing in his mouth.
Continuity mistake: When Flounder and Larry arrive at the Omega house for the party, sunlight can be seen coming through the windows, although it was night when they arrive.
Continuity mistake: During the Delta Rush Party, Pinto (then just a pledge) got a beer. Notice that, as the scene changes camera angles, the heads on the beers go up, down, and up again.
Continuity mistake: When Stork and his associate step conspicuously onto the curb to watch the parade the pompom's yellow tassels face front. When the man behind them says, "Excuse me, my kid can't see," the purple tassels face front.
Continuity mistake: When they are getting the girls from the other college, when the first girl comes down the stairs her broach is on the left of her top. When she is sitting down, the broach has moved to her right. It changes back to her left again after this shot and for the rest of the film.
Continuity mistake: In the cafeteria, Bloto puts stuff on his tray. Before the cut his bunch of bananas are on the side of the tray. After the cut the bunch is on the other side.
Continuity mistake: When one of the Delta Frat Guys is drinking beer in the frat, in his close up he is holding a mug by the handle, in the reverse shot he is not holding the handle.
Continuity mistake: When the Dean is on the phone in the middle of the night, his drunk wife gets her feet tangled in the phone cord, then falls off the bed, pulling the receiver off the hook. In the next shot showing her giggling on the floor, the phone cord is no longer visible.
Continuity mistake: When the "Deathmobile" first appears, it spins around 180° and is parked parallel to the curb in front of the Beauty Bar (just past the grandstand) when Bluto pops out dressed as a pirate. When seen next it's now at a 45° angle facing the grandstand in front of the Fashion Store, but it was never heard or seen moving between shots.
Continuity mistake: When the Deathmobile lines up across the street to take out the grandstand, the car reaches the grandstand about three times before it actually rams it. Even after one shot if the car reaching the grandstand, it cuts to D-Day yelling "Ramming Speed!" and then the car is seen back at its original position on the other side of the street.
Continuity mistake: When the Deltas are leaving the student court on masse, you can see Bluto followed by Flounder exiting the hall as Vernon shouts "I'm calling your national office." After several more seconds of Vernon shouting and Greg frantically slamming his gavel, it cuts to a shot of the doorway with Bluto and Flounder just walking up to it and stopping to grin at Vernon. They would've been long out of the room by then.