Continuity mistake: In the scene where Madame Zeroni is explaining to Elya Yelnats about the curse that will be bestowed upon him if he doesn't carry her up the mountain after presenting the pig to Myra's father, her blouse is a blue button-up with gold stripes and no collar. Then the camera looks at Elya, and then back at Madame Zeroni. When it looks back at Madame Zeroni, you can see that her blouse is now a gold button-up with a collar.
Continuity mistake: When Mr. Sir gets angry at the boy who said, "What happened to your face?" he asks the campers if he looks good and you see D-Tent sitting in the upper left hand corner, everyone is sitting down. In the close up of D-Tent, X-Ray and Armpit are standing then. In the next shot with Mr. Sir, you see Armpit and X-Ray going to sit down. Then back to Mr. Sir, you see X-Ray standing.
Continuity mistake: In the scene where Stanley and Zero are digging to find the chest toward the end of the movie, the background behind them is just a dirt wall. In a following shot upon discovering the box, there are stairs that lead to the hole. In the next shot, these stairs are gone again and it's just the hole again.
Continuity mistake: When Mr. Pedanski is explaining Camp Green Lake to Stanley, X-Ray, Armpit, and Squid come. Then right before X-Ray says, "Go ahead Pit" there is a shot with Mr. Pedanski and Stanley and there are two boys walking together. Then when we see Stanley and Mr. Pedanski again they're gone only for one boy.
Continuity mistake: In the scene at the end where the Yeltnats open the chest you can see Stanley's father with rubber gloves on, he takes his left glove off to look at the stock papers. You see him with his right glove on still, then Stanley takes one of the papers from his father and he doesn't have any gloves on, and in the next shot he has it back on his right hand.
Continuity mistake: In the scene when Zero and Stanley get to the top of God's Thumb Mountain, Stanley splashes Zero with some of the muddy water. Zero goes from having no mud on him, then having mud on him (before even getting in the water), to only having mud on his back (before getting in the water), to having mud on him (after in the water), to finally having no more mud on him (after being in the water).
Continuity mistake: At the end, right before the rainstorm comes, ZigZag jokes: "Say, I didn't know that Marian was a man's name." Mr. Sir replies: "It ain't" then ZigZag smiles and looks downward. The next shot, it zooms on Stanley (who is in front of ZigZag) and you can see that ZigZag has a blank expression on his face and is merely looking around.