Continuity mistake: When Charlie's mom and grandparents are watching the TV, hearing about the end of the Wonka contest, look at the TV. In the first shot, the left panel of the TV housing is missing. In the next immediate shot it is there, and remains for the rest of the scene.
Continuity mistake: When Charlie's grandad falls on him soon after getting news of his Golden Ticket win, one of the other old guys in the bed has a shocked look on his face. In the next shot however, the old guy now has his hand over his face and not enough time has passed for this to occur.
Continuity mistake: When Willy Wonka comes out of the factory to greet the children who will be touring that day, he walks down a red carpet. A minute or so later the lucky children walk up the same carpet. As the scenes cut back and forth between Wonka and the children the viewer sees a shadow on the carpet of the building next door. At one point the shadow has shifted noticeably and then reverts to its former position.
Continuity mistake: When Charlie first comes home after he's got the golden ticket, he hands the ticket to his grandfather to read. After he says, "You've done it Charlie." and hands the ticket back to Charlie, look carefully. The ticket is thinner, less wrinkled, and doesn't have any writing on it.
Continuity mistake: When Charlie visits his mother at the Laundry, he sits down at the washing bowl. When you see Charlie from behind you can see the big wooden spoon sticking out of the bowl. When the shot turns to the front of Charlie, he is stirring the laundry with the spoon. In the next shot of Charlie from behind the spoon is in the exact same spot as previously - it hasn't moved.
Continuity mistake: At the end of Veruca's song she sings "Don't care how, I want it now". In one shot her hands are at the far sides of the box, but in the next shot they are together at her sides.
Continuity mistake: As the case of wonka bars is being auctioned, and the auctioneer says "3000 pounds, 4500 pounds", his arms go from being at the edge of the table to next to his sides.
Continuity mistake: At the start of the movie, when the school children are running out of the school towards the candy store, the time visible on the school clock is 3 o'clock. At Bill's candy store right next door the time is 3.20.
Continuity mistake: After Charlie gets the chocolate bar for his birthday the position of his fingers on the bar change between shots.
Continuity mistake: When Charlie is working with Mr. Turpentine on the wart-removing potion, the bottles and cups on the table change between shots.
Continuity mistake: When the first "good egg" falls on the eggdacator, its position changes between shots.
Continuity mistake: When Charlie sees the newspaper about how the fifth ticket was faked, the position of the newspaper in the man's hands changes between shots.