Continuity: This is a mistake for the introduction for the later episodes. When Homer screams, he turns round. You see this in a wide shot. There are no boxes to the right of the door in the garage. However, two just appear out of thin air when he runs through the garage.

Continuity: When Homer's Vegas wife shows him the video in front of Marge, it shows Homer kissing Ned. This didn't happen when she showed it in the Vegas episode.

Continuity: When Bart leaves the school, you can see that his skateboard is green and perfectly flat. But when he is skating through the crowd and past the people at the bus stop, the skateboard has an orange stripe down the middle and is raised at the rear.

Continuity: For seasons 1 and 2, in the introduction Lisa narrowly misses Homer on her bike, then lets it roll into the garage. If you look closely, you can see the bike disappear before the screen moves.

Continuity: When Maggie goes through the checkout at the beginning, Marge's trolley is grey and has a red handle. But in the next shot, when Maggie pops out of the bag, the trolley has no red handle, and is a turquoise colour.

Continuity: In the bit where they sit on the sofa at the start of each episode, there is one rather long one where it starts off with the Simpsons dancing in a line, then gradually evolves into a circus with elephants and men dancing around fire. Look closely in between Homer's right leg and the dancing woman on his right. There is a pile of books on the little shelf underneath the lamp and telephone, and just as the camera starts zooming out from the line of dancing, the orange book on the left noticeably changes to purple.

Other: During the theme, the Simpsons' mailbox flag is on the wrong side of the mailbox. (Flags are always on a mailbox's right side, when viewed from the front. The one at the Simpson home is on the left side of their mailbox.).

Continuity: In the introduction for all episodes, initially Maggie's seat is light purple. However, in the wider shot of her and Marge, the seat changes to a burgundy colour.

Factual error: In the episode Regarding Margie, Moe has a double barrelled shotgun that fires four times. A double barrelled shotgun can only fire two shells before having to reload.

Continuity: In the episode where Homer builds a dog house. the notepad Homer draws the blueprint on, changes from having content on it to being blank so he can draw on it.

Continuity: Treehouse of Horror 18: When Marge puts the logo Hugh Laurie in the microwave, he splatters in the corner. Next shot the splatter is in the middle of the microwave.

Audio problem: In the episode where Homer is hosting gay marriages, at one point Homer is strangling Bart and tells Lisa to hold his spot. You can hear Lisa say, "Why you little," and you can hear Bart choking, but neither of their mouths is moving.

Factual error: In episode 19-7: "Husbands and Knives," the cover of "World's Finest Comics" 94 is shown on the wall at the comic book store. It features Superman with a sign that says, "Gotham or Bust," and Batman gulping. The actual cover of "World's Finest Comics" 94 shows Superman being sprayed with liquid kryptonite while Batman and Robin catch sight of him.

Continuity: In "Sex, Pies, and Idiot scrapes": When Homer has Snake cornered, the second rung on the ladder behind them is broken. In the next shot it's not broken, then it is again.

Factual error: When a comet is about to hit Springfield, everyone is standing on a hill in the shadow of it. But the shadow is still there even after it breaks up.

Continuity: On various occasions the front door, viewed from the inside of the house, has hinges - and therefore opens - on the wrong side, if you compare it to the shots of it from the outside.

Continuity: In the episode where Marge becomes a construction worker, one of the more recent ones, it is revealed that Bart is very allergic to shrimp. However, in the episode where Marge and Homer get "framed" for a murder and end up on "Frame Up", Bart says he was in the green room and that he "ate so much shrimp".

Continuity: Million Dollar Abie: When the bulls are stampeding, people who were at the top of the stadium and safe can be seen running in front of the bulls.

Continuity: Lewis changes from black to yellow when Milhouse dares Bart to pull Santa's beard off.

Deliberate "mistake": After Homer brings Santa's Little Helper home, Homer and Marge hug, and if you look behind them, the background is upside down. There is a picture hanging upside down, and there is a lamp which seems to be hanging from the ceiling. Then in the next shot, the background is normal.