Revealing mistake: After Lansbury makes her clothes start to move, her nightgown attacks someone and you can notice the strings that make the gown move.
Plot hole: When Miss Price, Professor Browne and the children return from their magical journey to the island of Naboombu and realize they no longer have the Star of Astroroth pendant, Miss Price says, "I should have known it would be quite impossible to take an object from one world into another." Yet, they had no problem taking themselves, the bed, blankets and pillows from one world into another.
Revealing mistake: When Ms Price plummets on her broom, a wire attached to her waist is visible.
Visible crew/equipment: When Ms Price tries to fly on her broom and she is launched upwards and wipes-out on the floor, she is replaced by a very obvious and much younger stunt double.
Audio problem: When Professor Brown and Miss Price are eating, he asks, "Why are you so interested in that?" His mouth doesn't move in sync with the words.
Revealing mistake: Toward the end of the movie Miss Price has done the 5 word spell to animate the objects. When the sword "knocks on the Miss Price's door", the strings are visible on the front of the sword.
Character mistake: The closing shot of a newspaper article shows the word "rumor", film is set in England where it's spelled "rumour".
Deliberate mistake: During Lansbury and Dr. Brown's dance scene under the water, the drawings behind them (with couples of fishes sitting on their seats) are a still drawing, no animation at all.
Continuity mistake: One of Mr. Browne's apples falls on the gravy when he is juggling, splashing his face and shirt. Later his shirt is spotless.
Revealing mistake: At Naboomboo, when the bear grabs Mr Brown and takes him to the cartoon beach, Mr Brown casts no shadow on the sand.
Continuity mistake: After trying to fly on her broom, Ms Price face plants on the floor, but a frame later, from a different angle, she is laying sideways.
Revealing mistake: When the armored army attacks the Germans, one of them falls on the floor and rolls away. Note the grass and you'll see that part he falls on has a darker color, revealing there was a safety mat underneath. (01:51:48)
Continuity mistake: At the library, Mr. Brown swaps from leaning on the center of a shelf, by the right of a column, to leaning on the center of the column.
Revealing mistake: When the cartoon lion introduces Mr. Brown as the referee, he starts playing with the football and suddenly the ball and his hand become transparent.
Continuity mistake: When Lansbury and Dr. Brown finish dancing, there's a wide shot of Lansbury giving a very small step forward to finish the dance. A second later, in a closer shot of her face, she moves as if she was repeating that very same movement.
Continuity mistake: At the lagoon, after Price and Brown win the cup and the hook falls, Paul is suddenly replaced with a completely different kid, older and much taller.
Audio problem: During the Germans' attack, Price is on her broom and tells Brown to protect the kids. Bullet traces fly next to her, but no sound is heard. Then it cuts to a shot of the Germans loading and firing, and now the bangs are head.
Continuity mistake: When the lion king blows the soccer ball into the goal, the ball disappears in the following wide angle.
Revealing mistake: When the white gown enters Ms. Price's house, before it starts dancing with Prof. Brown, a string holding it is visible.
Continuity mistake: The green skirt that comes alive smacks Ms. Price's nape and sends her glasses to the tip of her nose. In the following angle they are perfectly placed.
