Right after Harry sees the Mirror of Erised for the first time, the second time he comes back with Ron, he drops the cloak right by the door. Once they run a little further ahead, you can see the green cloth (aka Invisibility cloak) they used for computer imaging laying on the floor.

In the scene where the trio enter the commom room after being confronted by Fluffy, when the door shuts behind them you can see the feet of the crew member who was closing it.

In the flashback, when Voldemort kills Harry's parents, baby Harry can sit up and has hair, yet the baby Dumbledore places on the Dursleys' doorstep is much younger.

When Dumbledore is using the Put-Outer, from one shot, the streetlight closest to him, on his right, is still lit; a few shots later in a close-up, that light is out even though Dumbledore never took the light out.

On Dudley's birthday, when Mrs. Dursley wakes Harry and he sits up in bed, a cloth and hand brush are hanging inside the cupboard door. When Dudley shoves Harry back into the cupboard, you see a cloth and a dustpan, but no brush. When the family arrive back from the zoo, and Mr Dursley locks Harry in the cupboard, none of the three are present.

When Dudley is told how many presents he has, and he asks, "How many are there?" a cut to him shows that his fringe is a bit untidy. The shot cuts to Vernon, and when it cuts back to Dudley, his fringe is much neater.

When Harry receives his first letter, Dudley snatches it from him before he has a chance to open it. Dudley then gives it to Uncle Vernon, who says, "Who'd be writing to you?" Watch Dudley carefully -- he's mouthing the line.

When Harry and the Dursleys are in the living room while it is being showered with letters, Harry jumps up on the table to seize a letter. Watch his hand: He's holding one the entire time, only feigning catching them.

Right after Hagrid gives Dudley a tail, and he, Uncle Vernon and Aunt Petunia run around with him, they run out of sight -- they seemingly disappear into nowhere.

After Hagrid gives Dudley a tail, watch him in the background while Dudley runs around. You can see it's not Robbie Coltrane but a double with a beard.

When Harry and Hagrid are in Gringotts, Hagrid takes the letter from Professor Dumbledore from his pocket to give to the Head Goblin. The string it is tied with has a bow that runs from the top to bottom of the envelope, and the envelope is creased. When the Goblin takes it, the envelope is different -- the bow runs from left to right, and the envelope is not creased. In addition, the "TOP SECRET" stamp is positioned differently on each envelope, and the string in each instance covers a different part of the stamp. When viewed from where Harry and Hagrid are standing, the final shot of the envelope again shows it as being creased.

The Hogwarts Express leaves from platform nine and three-quarters, between platforms nine and ten at King's Cross station, London. The platforms shown in the film as nine and ten are, in fact, four and five (the only platforms that have a wall between them as shown in the film). The real platforms nine and ten are in a separate part of the real station. In addition, when Hagrid and Harry are on the footbridge, they are walking towards platform one, away from both the real platforms nine and ten and the film's platforms nine and ten. No wonder Harry feels lost when Hagrid leaves him to find the train on his own!

When Hermione first meets Harry and Ron, she fixes Harry's glasses. But two or three scene cuts earlier there is no tape around his glasses. Then it magically reappears in time for Hermione to fix.

On the train to Hogwarts, Hermione tells Harry and Ron that they need to get their school clothes on, as they will arrive soon. It is daytime outside. Yet the train arrives at Hogsmeade Station when it's dark - clearly not soon after.

At the start of term feast, after Harry is sorted into Gryffindor, he sits down on the right side of the table next to Ron. When the feast appears, Harry is on the other side of the table, next to Hermione.

In the scene when the kids first come in the Great Hall, on the table to right of the camera, you can see Oliver Wood. Next to him, there are some kids, but in the next shot, the kids are gone and Wood is on the corner of the table!

In the scene where Harry and Ron have just rushed into McGonagall's classroom, she transfigures from a cat on her desk to herself, walking towards them. In the first shot, we see the left side of her face, and she is not wearing glasses. When the shot changes so that she's facing Harry and Ron and we see the right side of her face, her glasses have appeared out of nowhere.

When Harry is taking notes in Potions class, he finishes writing all of the words to Snape's speech just as Snape turns to him. Yet, when Hermione nudges him, several seconds later, he is still writing.

In Potions class when Snape was talking, a shot showed Harry's handwriting to be small and the lines rather close together. In the next faraway shot, Harry's handwriting is huge and spaced out.

When Harry, Ron, and Hermione are in the staircases, watch the pictures on the right: they are not moving, but when the camera changes all the pictures are moving.

In the flying class scene, Hermione's hair is crimped. Later, when you see the class looking at Neville after his fall, you see that her hair is straight. The very next shot she's in, her hair's crimped again.

In the flying practice scene, after Malfoy gets ahold of Neville's Rememberall, he flies up with his broom and, after dialogue with Harry, he throws the globe away. Harry, after flying at least twenty meters after it, catches the globe in front of McGonagall's window, which is at least on the eighth floor of a tower. When Harry flies back to the others and lands, McGonagall almost instantly comes up behind him. Now wasn't that a bit too fast? She can't have Apparated, as no one can do that on Hogwarts grounds.

In the scene where Neville lost control of his broomstick during flying lessons, we see a shot of him going straight towards the castle wall (this is the first time he sees the wall). When you see him zooming towards the wall, there are many windows. However, when the shot changes and Neville actually bumps into the wall with his broomstick, there are no windows seen.

During the scene with the troll, Hermione crawls over to the sinks. If you look at the floor, you will see that there are only a few wet spots. In the very next shot, however, the whole floor is soaked (this occurs before the troll breaks all the sinks).

When the troll is about to swing at Harry for the third time with his club, Ron levitates his club. When the club falls, it hits the trolls head with a loud thump, then falls to the ground. But you never hear any sound of the club hitting the ground.

When Hermione is saying to Harry and Ron, "You won't make a fool of yourself- it's in your blood," Harry and Ron have several books with them, but straight after, right before the staircase moves, they have no books in their hands.

When Hagrid drags the Christmas tree into the castle, in the first shot, there is no snow on his hair although he has supposedly been outside for some time. When the camera angle changes his hair is now covered with snow.

When Harry is on his way to the restricted section of the library under his Invisibility Cloak, we see a shot of his hand holding the lantern (the first shot in the scene). You can see the end of his jumper. In the next shot, however, the end of his jumper is under the cloak, but it had no time to get there between shots.

In the scene in the library's restricted section, Harry puts down his cloak and then his lamp. The lamp is several inches away from the cloak. When Filch enters Harry grabs the cloak and suddenly the lamp is now on top of the cloak, causing it to fall.

During the Quidditch match, Hermione looks in her binoculars up to where Harry is. If you look at the reflection in the binoculars, you can see Harry flailing around. She then looks over at Snape, but when we see the reflection in the binoculars, we still see Harry, as if she were looking at him.

In the scene where Harry, Ron and Hermione come with Filch to Hagrid to go into the dark forest, watch the lamp Hagrid sets down. Filch says something like "A sorry lot this, Hagrid." Then the shot cuts to Hagrid (look at the lamp) then to Filch again who says "Oh good god man, you're not still on about that bloody dragon, are you?" then to Hagrid again. The lamp changes position between these shots.

When Harry, Ron, And Hermione are heading to Hagrid's hut, you see a group of three people behind them walk into another corridor. A second or two later, the same group walks into the same corridor.

When Harry, Ron and Hermione rush to Hagrid after end-of-the-year exams, and Harry is saying something that ends with "why didn't I see it before," Emma is mouthing his lines.

In the scene when Harry, Ron and Hermione run to Hagrid's hut to ask him where he got his dragon from, Hagrid tells them a stranger wearing a hood sold it to him. Hagrid then says "seemed quite glad to get rid of it as a matter of fact." When he says "...as a matter of fact," his mouth doesn't move.

When the three children get past Fluffy because the harp is playing, as Fluffy wakes he dribbles on Ron's shoulder. However, when they fall down into the Devil's Snare, his shirt is completely dry.

During the chess game when the queen drives her sword through Ron's knight, if you pause it just right, you can clearly tell that it's a stunt double falling off the horse.

In the chess scene, when Ron falls off the horse, he is lying on his side on the floor with one knee bent so that one foot is higher than the other. When Harry and Hermione run over to check on him, one foot is on top of the other.

When Professor Quirrell removes his head wrap to reveal the concealed Voldemort, Quirrell is obviously bald. However, if you carefully watch the scene with the troll, Quirrell's sideburns are clearly present after he shudders as the troll exhales.

When Harry puts his hands on Quirrell's face and pushes him against the wall, you can see the wall behind Quirrel is flat; in the next shot, there are two large holes in the wall; in the next shot, the wall is flat again.

When Harry is boarding the Hogwarts Express to go home, Hagrid stands on the platform to wave goodbye. He is wearing a coat and looks huge, as usual, but you can see when he waves that his hand seems rather small compared to the rest of his huge frame.