Goofs

(at around 1h 50 mins) When Harry and Ron are in the car being chased by the spiders, Ron switches gears with Harry's hand over his. The clothing sleeves shown on them in that brief shot are not the clothes they're wearing in that scene, but what they'd worn in the earlier flying car scene at the beginning of the movie.

(at around 34 mins) Ron receives the "Howler" from his mother. After his owl, Errol, crashes into the table, you can see that the red envelope is open. As Ron removes it from Errol's mouth. We then see Ron breaking the seal on this envelope so he can read it.

(at around 57 mins) When Harry's hand is hit by the bludger in the Quidditch scene his arm guard is clearly seen flying off his arm but the next time you see his arm, the arm guard is still there.

Throughout the movie, Harry's eyes change between green and blue.

(at around 1h 5 mins) When Professor Lockhart is knocked backwards by Professor Snape's charm during their duel, his wand can be seen flying through the air. When he lands, however, the wand is back in his hand.

Lockhart gets to the end of the slide that leads to the Chamber Of Secrets much faster than Harry and Ron do. He may be heavier than them, but not that much heavier.

When Dumbledore hands the sword to Harry in the end, Harry grabs it by the blade. Magical sword or not, the blade should wound him.

Unless the car has magic safety features, the encounter with the tree (crashing into it, being struck by it, falling from the tree) should hurt the boys more severely than it does, including damage to the spine.

In the last scene in Dumbledore's office in the movie, Dumbledore is explaining why the Sorting Hat placed Harry in Gryffindor. During that exchange Dumbledore says "It's true. You possess many of the qualities that Voldemort himself prizes." (This is stated in the original English and in the Castillano (Spanish) dubbing.)

However in the same scene in the book, Dumbledore says "You happen to have many qualities Salazar Slytherin prized in his hand-picked students."

Dumbledore should have referenced Slytherin, not Voldemort, in the movie.

(at around 20 mins) The scene in Flourish & Blotts, where Hermione's parents are seen inside Diagon Alley, has been called a plot hole. Normally, Muggles cannot enter, or see, Diagon Alley. However, the Grangers are accompanied by Hermione, who, as a witch, would know how to enter through the Leaky Cauldron (and be able to see the pub). In the book, the Grangers comment to Mr. Weasley about having visited Gringotts to exchange their Muggle money for Wizarding money. If this is the case, they obviously aren't the first Muggles to enter Diagon Alley (indeed there have been numerous children who must have been taken there by their parents alongside a school staff member to buy their first year equipment for Hogwarts).

(at around 35 mins) In Professor Lockhart's first lesson, he mentions that he 'didn't get rid of the Bandon Banshee by smiling at him.' Banshees are always female. Possibly another indication of how stupid Lockhart is.

(at around 17 mins) When Harry first meets Hermione in Diagon Alley, she casts a spell that fixes his broken glasses. (Arthur Weasley did this in the book.) Underage wizards/witches aren't allowed to use magic outside of school, yet Hermione isn't prosecuted. In a heavily populated area, it's impossible to trace any spell to a specific person.

(at around 1h 4 mins) For most of the movie, it is shown that Moaning Myrtle is not solid, and that solid objects pass through her. However, when she jumps into the toilet, the water splashes. A splash can only be made by a solid object having sudden impact with water (this was also in the book). However, traditional ghost lore has ghosts able to move physical objects when they (the ghosts) are in an aggravated state of emotion, so we can assume the book/film follows that notion.

(at around 11 mins) The magic clock in the Weasley home shows a "Dentist" label. The series' running gag is that the Wizarding world has no idea what dentists are and what they do. However, this label was added by Arthur Weasley, a Muggle Studies anthropologist who could easily have learned about dentists through his studies.

The green puppet used to represent Dobby during the shoot is reflected in Harry's glasses.

(at around 48 mins) At the beginning of the transfiguration lesson, the writing on the blackboard behind Professor McGonagall is reversed, and this has been reported as a flipped shot. Further observation reveals that the right-hand board is, for undisclosed wizardly reasons, a mirror image of the left-hand board and so this might not seem to be an error. However, near the end of the scene, when Hermione asks what's in the Chamber, as McGonagall is answering 'The Chamber is said to be home...', she's in front of the right-side board and we get a better look. Although the drawing is indeed a mirror image of the left board, the writing is still flipped (we can see the words Lesson VI in front of the drawn peacock's beak as being backwards)

(at around 1 min) When Harry is flipping through his photo album at the very beginning of the movie, he views a picture of himself, Ron, and Hermione that should've been taken during the last school year, however, it's clearly a recent photograph as Ron and Harry both sport longer hair, and Hermione's hair is curlier.

(at around 37 mins) When the pixies drop Neville on the chandelier, the pointy plastic ears used when the pixies pull him up are still on him after they let go.

(at around 1h 19 mins) When Crabbe and Goyle pluck the chocolate cupcakes out of mid-air, you can see the shadow of the string on Goyle's face.

It is not clear how Dobby can be forced into slavery when he can teleport around easily without his master's knowledge - even to steal letters supposedly delivered by owls. Additionally he can cast spells with his hand, even stopping his former master and not getting destroyed in revenge. His magic is strong and not dependent of Lucius. The slavery should be enforced by some considerable force or spell to be meaningful since Dobby can just disappear at any given time.

(at around 1h 7 mins) When Snape leans over to pick Draco up after he has been thrown through the air by Harry's spell in the dueling scene, a crew member in blue jeans can be seen on the far left.

In the scene where Ron and Harry turn into Crabbe and Goyle, as they leave a crew member can be seen crouching in the background behind Malfoy.

(at around 1h 45 mins) When the spiders are coming out in great numbers, stage lights are visible.

(at around 27 mins) When in the Whomping Willow, Ron asks, "What's happening?" and Harry replies, "I don't know." After a few other shots, in the next two front close-ups of the boys as they scream, Harry, Ron and Hedwig are not alone in the car. A crew member's hand is quite visible holding the bottom of Hedwig's cage and in the 2nd close-up is actually laying the cage on its side.

(at around 28 mins) When the Weasleys' enchanted car has ejected them and Ron and Harry are chasing the car, you can see the hand and silhouette of the driver.

(at around 8 mins) In Harry Potter and the Sorcerer's Stone (2001), #4 Privet Drive is a detached home. Only a garage connects it to the other similar homes on one side. A double car-garage home of a different design that is not attached to the Dursley's house (save for a fence that leads to the garden) stands on the other side. In this film, when Uncle Vernon is putting the bars on Harry's window, the house is clearly connected on both sides by two like homes, and there is no sign of the double car-garage house from the first film. Also, the trees from the first film have disappeared.

The questions Harry asks to Moaning Myrtle should have been asked by Dumbledore decades ago. He was a teacher when the Chamber was opened last time, and as a Headmaster, he definitely knows "Moaning" Myrtle Warren, the last victim of the Basilisk.

The original plan of Slytherin was to use the Basilisk to kill all Muggle-born students, but only them. However, if Harry, who is Pure-blood, can die from eye contact with the Basilisk, then Slytherin risked countless lives he wouldn't want to, as the Basilisk could kill anyone accidentally.

Even if only Harry can understand the whispering, others should hear a snake's hiss too. It' not telepathic talk, only an unknown language for them. That wouldn't make the Basilisk's voice inaudible. However, nobody else in the movie (and in the book) can hear it.

The size of the Basilisk is highly exaggerated, as it clearly wouldn't fit into the pipe that leads to the Chamber.

(at around 1h 35 mins) McGonagall's new rules include "all students must be accompanied by a teacher to a lesson". However, it is later shown that there are only 9 teachers (including Dumbledore, Hagrid, the nurse and Filch). With 280 students in the school, this rule is impossible.

(at around 1h 5 mins) When Snape uses "Expelliarmus" on Lockhart, he is thrown through the air and still has his wand in his hand afterwards. The spell is supposed to make the opponent lose their wand and it is very unlikely that Snape would fail to perform the spell correctly.

(at around 48 mins) During Professor McGonagall's class where she discussed the history of the Chamber of Secrets, Crabbe, Goyle and Draco Malfoy can be seen wearing a different colored necktie (just like the Ravenclaws) to their house.

(at around 3 mins) When Dobby starts to cry and goes to jump off the bed, Harry's eyes follow him, but don't keep up with his speed. The on-set puppet Dobby was not as fast as the CGI Dobby that was added in later.

After Harry catches the Snitch and the Bludger continues to attack him, he puts his full weight on his broken right arm as he sits up to get out of its way.

Harry tells Dumbledore that the reason why the Sorting Hat put him in Gryffindor was because he asked it to. He didn't actually ask it to put him in Gryffindor specifically, only to not put him in Slytherin.