Audio problem: When Mr. Wonka bites into a teacup at the end of the song of the room with the Chocolate River, you hear a crunching sound, yet it looks like he has to "tear" the cup a bit. How can he crunch on somethng that requires him to tear at it? [In an interview, Gene Wilder stated the cup was made out of wax - not excusing the mistake, but in case anyone was wondering...]
Continuity mistake: When Charlie is working with Mr. Turpentine on the wart-removing potion, the bottles and cups on the table change between shots.
Revealing mistake: When Mrs. Teevee puts the shrunken Mike into her purse, it is a very obvious fake Mike.
Continuity mistake: When the first "good egg" falls on the eggdacator, its position changes between shots.
Audio problem: When the red shirt kid comes into the classroom and talks about the tickets, in the closeup, he's facing inward. When he says "You've got to buy Wonka bars", and the shot goes wide, he's facing the door, turning to his right to leave. His mouth doesn't appear to be moving.
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.
Continuity mistake: After Wonka tells Mr. Salt a waterfall mixing chocolate gets it just right, both men are very close together, but the next shot of them shows Salt further away from Wonka than before.
Continuity mistake: In the scene after Charlie brings home the loaf of bread, his mom moves in front of the television set near Grandparents George and Georgina, but the closeup of George and Georgina shows Charlie's mom nowhere near the TV set.
Continuity mistake: When Wonka enters the shrinking corridor, he pauses in front of the wooden door, to the right of the viewer but the next shot shows him further to the left.
Continuity mistake: When Charlie gives his pay to his mom, Grandparents George and Georgina are asleep but their head still change from lying at an angle to straight as the shots change.
Revealing mistake: As Veruca sings "I want it now" in the egg room, the plastic seams on a few of the golden eggs are quite visible, along with their 'dimpling' near the tops and bottoms, as the Oompa Loopmas pass them around for polishing.
Continuity mistake: Outside the Inventing Room, Veruca and her father stand about a foot apart from each other, but the next quick shot shows Veruca standing in front of her dad's left arm.
Continuity mistake: When Augustus falls into the chocolate river, Wonka's right hand is resting on the top of his cane, which is planted in the ground, but the next shot shows his right arm up, and bent at the elbow.
Continuity mistake: When Veruca throws the golden wrap at Wonka, the table holding the wrapper is head-on to the viewer, implying Wonka's point of view, but after Veruca throws the wrapper on Wonka, the table is off screen and 90° to the left of Wonka and the other factory guests.
Continuity mistake: In the "I Want it Now" musical number, Veruca grabs some golden egg wrapper and throws it on Wonka. When she does, the table with the wrapping is immediately behind her, but when the scene cuts to her after she has thrown the wrapper on Wonka, the table has disappeared.
Continuity mistake: When the guests enters Wonka's Fizzy Lifting room, Veruca Salt and Mike Teevee are standing next to each other, when Mike turns away from Veruca and takes a step. The next shot shows them both close together again.
Audio problem: When Charlie and Grandpa Joe are singing the "Golden Ticket" song, Grandpa Joe says, "Watch my speed!", but his mouth does not move to match the words.
Visible crew/equipment: When everybody first comes in the main room with the chocolate river, there is a shot of all of them standing in the doorway. At the bottom of the scene is the shadow of the camera.
Visible crew/equipment: In the Fizzy Lifting Drink scene, as Wonka leaves the room, a bubble machine is just visible at the bottom left of the screen.
Visible crew/equipment: There is a cameraman shooting near the gate of Wonka's factory: he is strategically placed to get up close shots shown in the movie yet he blends in to the crowd to make the movie audience think he is one of the many media technicians filming the event of Wonka opening his factory. Later, when the guests are passing through the gate, the cameraman has disappeared.
Suggested correction: The Cameraman is part of the news crew that was filming the event all around. Not a mistake.