Continuity mistake: In the final dance scene, there are supports on the ground for the machine guns when Roxie and Velma are not holding the guns. These supports disappear when Roxie and Velma are holding the guns.
Continuity mistake: When posing for the photographers at Roxie's trial, whenever we see Billy and Roxie from the front, Billy has his arm all the way around Roxie with his hand resting on her stomach. Yet whenever we see them from behind, his hand is resting in the middle of her back.
Continuity mistake: In the scene where Velma offers Roxy some chocolates, Velma puts the box down on her left. In the next shot, it is at the corner of the table, on Velma's right, with the long side facing Roxy. In the next shot the short side is facing Roxy, then the long side again.
Continuity mistake: In the scene where Roxie gives Velma her laundry the money in Velma's top moves from hardly seen to almost all the way out.
Continuity mistake: At Roxie's trial when Billy is examining Amos and talking about Roxie's baby, during the close-ups of Amos, the camera goes to Billy when he's asking a question and Amos when he's answering a question. When Billy is ranting about Amos not even asking Roxie if he was the father, during the shots of Amos, Billy is MUCH closer to the witness stand than when the camera goes to his shots. (01:22:55)