There's Something About Mary (1998) - 36 mistakes

Visible crew/equipment: When Ted and Dom are looking at Mary, speaking with Warren and Tad from behind the tree, if you look carefully you can see the camera and crew in the reflection in Ted's glasses.

Continuity: In the confrontation scene where all of Mary's admirers are forcing her to choose between them, Woogie is sat on the couch with a pile of Mary's shoes. Every time the camera shoots back to him, you will notice that the position of the shoes changes each time. This is also mentioned by the directors on the DVD commentary.

Continuity: About one hour into this movie, when Healy is playing tag with the 'Neary group people' he goes for the touch down and Warren runs after him to get the ball. As Warren first dives for the ball, you can see that he has three red tags attached to his back, in the next shot as he lands you can see that the tags have disappeared.

Continuity: This is during the scene on the outside steps of Mary's office, when Mary and Ted see each other for the first time. A suit-wearing businessman comes from the left side of the screen behind Mary twice. This happens when Mary is saying "Ted? Is...Is that you?" and the camera goes back and forth between Ted and Mary.

Factual error: The chiropractor that Ben Stiller's character visits says "Tender fascial tissue left of L7" as he is treating his back. However there are only 5 Lumbar Vertebra in our back, L7 doesn't exist.

Continuity: When Pat is spying on Mary, the first morning he spies on her, Mary leaves her house and walks down to a deck and she throws Herb an apple. In a wide shot, on the barrel next to Herb is a cup, yet in the following closeup a bottle of whisky appears from nowhere.

Audio problem: When Mrs. Jenson see's Ted's thing caught in his zipper, she turns and yells "Holy Shit!" Her lips however don't reflect these heard words.

Visible crew/equipment: When Mary is having lunch with her three friends and she is talking about the kind of guy she wants to meet, you can see the boom mic in the reflection of her sunglasses.

Visible crew/equipment: When Mary, and Ted are driving with the dog on top of the car, when Ted opens the door you can see the camera operator, and the boom mic reflect from the car door.

Continuity: When Ben Stiller got his "frank and beans" caught in the zipper, the friendly police officer thought he would assist with the problem. He unbuttoned his sleeves and rolled them up, but then the next camera shot showed them buttoned up, and had to be rolled up again.

Continuity: There is a scene where Ted and Mary are on a date and Mary is eating candy floss. There is a cut from her holding the candy floss where she and Ted talk and she doesn't eat any of it at all. Next shot showing the candy floss however, and there is a lot less than there was a couple of seconds before.

Revealing: When Puffy the dog bites Ted and pulls him along, Ted digs his fingermails into the floor, they scrape along, making marks. If you look very closely you can see faint pre-made marks made in the floor, where he drags his nails along.

Continuity: When we see the first shot of the meeting Dom is holding, you can see the meeting table with loads of sheets on it. Then it changes to a shot of Dom standing by his big pad (just before Ted runs and yells "Mary's a fox!"), and the sheets on the table have moved around and some have vanished.

Continuity: When Ted is fighting with the dog, the carpet under the table changes back and forth between flat and bunched up.

Continuity: Tucker shows his ID bending its left side in the wide angles, yet in the close-up it appears straight.

Continuity: When Puffy the dog goes crazy, he bites Ted's neck and Ted crashes onto the counter, smashing into some wine glasses and cups. Between a closeup and a wideshot, the smashed glass that lays around Ted changes. Also in the closeup Ted is fully on the counter, yet in the wideshot he is half on the counter, with his legs hanging off of the side.

Continuity: When Mary says to Ted "I have a lot of fun with him" about Warren, her hair falls over her eye. In the next shot it is pushed back.

Continuity: In the scene where Ted is sitting on his bed, he pulls out his wallet to look at a picture of Mary. When he first pulls it out, he is looking at it from the side. But when they actually show you the face of the picture, it is upright.

Continuity: When Pat is round Mary's, he is holding the dog. Between a wideshot and closeup, the way he holds the dog changes.

Continuity: When the dog is on fire, Pat gets a vase of water and pours it on the dog. In a wide shot the dog is on it's back, with all fours pointed up in the air. Yet in the closeup of the water being poured on the dog, the dog is on it's stomach just sitting down properly. This is obviously due to the switch of the fake dog to the real dog.

Continuity: When Mary has lunch with three friends, in a wide shot one of her friends picks up her drink and brings it to face level. In the following closeup of her, she brings the drink to her face again.

Continuity: The crowd that watches the guy fight with Warren and Ted near the beginning keeps on changing. People move where they're standing between shots and the arrangment of the crowd changes throughout the scene between shots too.

Deliberate "mistake": The man kissing Cameron Diaz in that last shot (when the homeless guy shoots the drummer) is not Ben Stiller, noticeable by his much taller, slender figure.

Continuity: When Ted and Mary are sitting on top of the car, Mary looks at her watch to see what the time is, but if you look closely, her watch is facing the camera, so there is no way she could have seen what the time was.

Visible crew/equipment: Just before Warren's fishing hook gets stuck in Ted's lip, the camera pans from showing Warren fishing to Ted and Mary. Here you can see the reflection of the crew on the ground and finally on Ted and Mary when they are standing there.

Factual error: Ben Stiller takes Cameron Diaz to the prom in 1985, but picks her up in a car made well after that; it has the newer-style headlamps.

Factual error: When Ben Stiller gets done "cleaning the pipes", he looks around the bathroom for "the missing hair gel", it is shown hanging from his ear when he answers the door. This is somewhat unrealistic. This glob of "hair gel" would never have hung onto his ear for as long as it did. It would have dripped onto his shoulder long before he reached the door.

Continuity: When the dog is dead, Pat tries to revive it by using some wires. When it fails, he puts the wires on the couch then peeks into the kitchen to see what Mary and Magda are up to. Then in the next closeup of the dog, the wires how moved to laying on his stomach.

Continuity: In the scene at the fairground, Cameron Diaz is holding a stick of very abundant cotton candy. The camera pans away for a few seconds, and when it returns the cotton candy is almost completely finished.

Deliberate "mistake": When Ben Stiller gets done "cleaning the pipes", he looks around the bathroom for "the missing hair gel", he should have known where it was simply by his senses. Earlobes have feeling in them. He should have felt something wet on his earlobe. He also would have felt it dangling from his earlobe.

Continuity: When Ted is laying in bed, he gets up and pushes his blue and red sleeping bags further down the bed, just before taking his picture of Mary out of his wallet. Between shots the position of the sleeping bags changes greatly.

Continuity: At the end of the film, when the camera is focused on all of Mary's suitors in her apartment, you clearly hear Matt Dillon say "Dom?!" off camera (as if he entered the room and was surprised to see Woogie there).  A few seconds later, he bursts through the door, sees Woogie and says "Dom?!".

Continuity: Ted makes fingernail marks in the floor when Puffy is pulling him along. Two things wrong: His fingernails aren't even touching the floor when he makes them, and the marks seem to disappear in almost all of the long shots.

Continuity: When Ted sees Mary for the first time in years, the hood on his sweatshirt changes from his back to his right shoulder.

Revealing: When the investigator takes Ted's head and starts slamming it on the table after Ted got finished telling them about the hitchhiker, Ted's head never hits the table but his own hand.

Continuity: Ben Stiller gets "hooked" with Warren's fishing line, getting a hook that quite noticeably has the prongs sticking out of his cheek when they are removing it. In the next scene, however, no scar, and no sign of the injury exists.