Lisa's Pony - S3-E8
Continuity mistake: After Homer watches the tape, Marge suddenly appears beside him. (00:07:30)
Tree House of Horror II: A Simpsons Halloween - S3-E7
Continuity mistake: At school, there are two rows to the right of where Bart is sitting. This keeps changing from two rows to one row during the entire scene. (00:11:00 - 00:12:15)
Like Father, Like Klown - S3-E6
Continuity mistake: When Bart and Lisa go to see Rev. Lovejoy, the objects on his desk keep disappearing/reappearing. (00:13:05)
Continuity mistake: Bart puts his lucky red hat on the hat holder. It disappears in the next shot. (00:07:10)
Continuity mistake: In the Wiggum's house the parent's bedroom changes style several times. When it is first seen the cupboard is opposite the door (When Chief Wiggum is looking into the room after climbing the stairs). Then it is on the wall running across from the doorway later when Chief Wiggum enters the room. When the Chief puts the Police Master key on his bed post the doorway is behind the bed and the bed is opposite the cupboard. Later when Bart steals the key the bed is seen parallel to the doorway.
Continuity mistake: After Bart and Ralph have just visited the cake shop they have chocolate and icing all around their mouths. Also they are carrying the 'Newly Weds'. In the next shot where they walk around the corner the chocolate, icing and model bride and groom have all disappeared.
Continuity mistake: At the Penitentiary, Jimbo's video camera appears and disappears from nowhere. He isn't seen carrying it on him.
Continuity mistake: When Homer jumps in the car having completed the Fatherhood test and drives off to see Bart race. The car shifts from reverse to forward without Homer moving a gearstick. (00:18:40)
Homer vs. Lisa and the 8th Commandment - S2-E13
Continuity mistake: When Homer is sitting watching cable, the rest of the family comes home and one of them is carrying a plant in a pot, which is put down next to the couch. While they watch and watch cable, it grows very tall and then withers down. When Homer goes behind the TV and starts kissing the wires, the plant has moved to next to the doorway and is suddenly fully grown again.
Tree House of Horror VII - S8-E1
Continuity mistake: In 'The Thing and I' when Homer and Marge return from driving around in the rain, there is no doorknocker on the door. Then in the shot where Hugo escapes, we see the door open with red scratches on it, and there is a doorknocker. Then later when everyone leaves to find Hugo, it's gone again. (00:02:40 - 00:04:55)
The Simpsons Halloween Special: Tree House of Horror - S2-E3
Continuity mistake: When Bart is unpacking his things from the box, if you look at the mantelpiece, we can see that there is a candle on the right hand side of it. But later on, there is a candle on the left hand side which wasn't previously there. (00:02:30 - 00:03:15)
Character mistake: When Homer discovers that the Leftorium is going out of business, there is a sign that says 'Coming Soon: Gum for Less' beside the store. Later on, though, Ned says the new store is becoming 'Libertarian Party Headquarters.' (00:15:50 - 00:19:15)
Suggested correction: The sign is just an advertising poster that's on a wall. It's not in front of the leftorium.
Audio problem: At the end, where Homer is carrying Mark Hamill out of the theater and Mark says, "Shoot, I forgot my Light saber", his mouth doesn't match what he says, and it keeps moving when he's quiet.
When You Dish Upon a Star - S10-E5
Continuity mistake: In the shot just before Alec gets hit by a tree branch, his watch is missing but in the next shot, his watch gets snagged on something.
Special Edna (a.k.a. Love and Marking) - S14-E7
Deliberate mistake: When Bart and Edna are watching "Holes" in the IMAX theater, Edna sighs and pulls out a locket which we can see the back of. After opening it up to reveal pictures of her and Seymour, we find out its actually a triptych when she opens up another image of Seymour's mother. From the way she unfolds this extra picture, Seymour's mother would have had to be facing outwards, but in the previous shot the back of the locket was blank.
Itchy and Scratchy: The Movie - S4-E6
Continuity mistake: When Maggie is driving Homer's car, a man is behind him. He is seen waving his left arm but when the shot changes to Maggie he is waving his right arm. (00:14:50)
Continuity mistake: When Homer is having the thanksgiving dinner at Moe's, he isn't wearing a tie, but between shots he suddenly gains a tie. (00:20:35)
Continuity mistake: When Lisa starts to drive away with Homer's pig, Marge is screaming 'No.' On Lisa's close up we can see Marge briefly to the left of the screen and her mouth isn't shouting.
Other mistake: The doctor in the insane asylum shows a video that shows a child Ned Flanders from 30 years ago. Ned is 60.
Like Father, Like Klown - S3-E6
Other mistake: When Krusty dials '1-909-SEX-CHAT,' he presses '90190' on the phone. (00:03:50)