Continuity mistake: When Lois is outside, the mail lady gives her Peter's check. The front door has no window on the outside, yet inside there is one. (00:14:25)
The Thin White Line (1) - S3-E1
Continuity mistake: Brian says Lois' toast is ready and it pops up, but in the next shot when the family is applauding him, the toast is missing and the toaster lever is pushed down. (00:07:20)
Revealing mistake: Peter's right eye overlaps his nose when he's watching TV with his family.
Something, Something, Something, Dark Side - S8-E20
Continuity mistake: Dak sits in the back of the snowspeeder and says "Right now, I feel like I could take on the whole empire myself" so Luke gets out. Dak is in back when he flies out but when he is in space he is now sitting in the front.
Farmer Guy - S11-E20
Continuity mistake: When Brian enters the farm house, Meg is on the floor unconscious on her back with her face up, but the next shot when the rest of the Griffins enter, Meg's head is turned to her left.
Continuity mistake: When Stewie jumps off the side of the hot air balloon, he has no rope attached to his ankle. Next shot they show him hanging from the hot air balloon from a rope tied to his ankle.
Continuity mistake: When Mort goes into Stewie's room, there is a sign on the door that tells Brian to stay out of his room. A few minutes later when Brian and Stewie enter the room, there is no sign on the door.
Other mistake: When the family is driving to New York, another red car passes in front of them from the right where there is no road. (00:09:35)
Suggested correction: Usually this would be right, but it's evident by their positioning that Peter is actually driving his car right in the middle of the road on the dotted line and not staying in one lane. This is why the truck passes on the left to get in front and then the car on the right, both also getting centered on the dotted line.
The Thin White Line (1) - S3-E1
Continuity mistake: Brian is at a nursing home playing checkers with a lady. When he gets up, the checker board vanishes. (00:19:20)
Brian's Got a Brand New Bag - S8-E4
Continuity mistake: When Stewie goes down the stairs in his bed, when he hits the front door, the door opens outwards outside. It always opens towards the inside. Plus in this episode, the door is brown when he rolls outside. Next scene and the other times in the show it's a red door.
And Then There Were Fewer - S9-E1
Other mistake: As Joe is driving up to the house, just before coming to a complete stop, you can see that his window is completely closed. After stopping, Peter says "Joe?" Joe says "Peter?" Joe's window is now fully open. Trouble is, Joe seems to be completely surprised by Peter standing there which implies he never saw Peter even after stopping. His window has mysteriously opened immediately. (00:04:05)
Friends Without Benefits - S11-E7
Continuity mistake: When Meg is at the movie theater with her date, she starts sweating and changes her shirt to a clean one she gets out of her purse. When they get back home, Meg no longer has her purse.
Continuity mistake: Stewie puts the gun and pictures in a bag and throws them in the trash can to get rid of the evidence. When Joe takes the lid off, he just reaches in like Stewie had put them in there separately and not in a bag.
Continuity mistake: When the black knight appears and says to Peter "What are you doing with my girl!?", there is a pitcher and a basket with a chicken leg on the table. But on the next shot where the camera is facing to Peter, both the pitcher and the basket disappear. (00:17:20)
Continuity mistake: When Meg's boss tells her to fire Peter, he has plungers on his nipples. He walks over to Meg and takes them off. A second later his shirt is tucked in without Peter being able to tuck it in. He's holding plungers in both hands.
There's Something About Paulie - S2-E16
Continuity mistake: When Paulie is eating dinner with Peter, his pile of mashed potatoes keeps changing from white to green.
Brian's Got a Brand New Bag - S8-E4
Continuity mistake: Towards the end of the episode, Brian walks in with Rita's soup. Notice there are no pill bottles on her nightstand. As soon as he sits the soup down, 3 bottles appear out of nowhere. Then, after Brian gives her the pills, the bottles disappear again. (00:03:02 - 00:03:28)
'Family Guy' Through the Years - S16-E16
Factual error: In the scene at the Disco, Peter and Quagmire both transpose "Viet Cong" but with "Donkey Kong." However, the segment is supposed to be taking place in 1973, meanwhile "Donkey Kong" wasn't released until 1981.
Other mistake: Joe salutes Quagmire's Dad. His legs are paralyzed, yet he uses them to push himself backward in his wheelchair.
Screams of Silence: The Story of Brenda Q - S10-E3
Other mistake: This episode is the only one in the entire series where there's a peephole in the door.