Factual error: During the orphans' rendition of "You're Never Fully Dressed Without a Smile" Molly is seen with a plastic drink bottle (that makes a plastic-bottle-esque "thunk" when thrown). The movie takes place in 1933, however polyethylene terephthalate (the kind of plastic used for drink bottles) was not developed until 1941.
Continuity mistake: In the scene where Rooster, Lily, and Ms. Hannigan are singing "Easy Street" and dancing on the stairs, Ms. Hannigan's foot goes into the wall creating a hole, but that hole is no longer visible in following shots. Also, you can see the outline in the wall where her foot is suppose to go.
Continuity mistake: When Rooster is in the hallway close to the railing, notice the colour of his shirt and suspenders. Then notice when he leaps on top of the railing and is spinning around, all the sudden his shirt color is different and you cannot see his face, but when he is done spinning the shirt color is the same as first seen.
Factual error: Throughout the movie, all the women (with the exception of Miss Hannigan) are shown to be wearing full coverage pantyhose (you can most see this in dance numbers). Pantyhose that covered all of the leg and buttocks were not invented until 1940 (Annie is set in the 30s). Any hosiery worn prior to that would have been stocking type that only came to the top of the knee.
Audio problem: When Ms. Hannigan is singing "little girls", the sounds that the two bottles that she clinks make a glass-against-glass sound; however, the bottle that she dumps into the bathtub floats in the water like plastic instead of sinking like glass would. (00:00:05)
Continuity mistake: During the final scene, Annie and Daddy Warbucks are watching a huge fireworks display. Dozens of fireworks are going off simultaneously and all the bursts are either blue or pink. In the close-up shots of Annie and Daddy Warbucks, only an occasional flash of light illuminates them and it is always orange.