Continuity mistake: During the scene in which Jerry and Avery break up we see him comforting her right before she punches him. When the shot is from behind him you can see that he is holding her and stroking her face with his right hand. As the camera switches angle to face him his hands are now at his sides.
Continuity mistake: When Jerry's at Dorothy's house, Dorothy and her sister bump into each other and Dorothy gets pizza on her shirt. When she's changing, there's a shot of her sister handing her the black top, then about a second later it cuts to a shot of Dorothy with the top on, fishing her hair out from the collar - how did she get it on so fast?
Continuity mistake: When Jerry is leaving his firm he brings out a box of personal stuff from his office before making his speech, but doesn't take it with him when he leaves with the goldfish and Renee Zellweger.
Suggested correction: This is deliberate, he decides to leave his goods behind as a show of defiance.
Continuity mistake: When Rod and Jerry are talking in the shower area there is a red sign behind Rod that changes its letters between shots.
Continuity mistake: In the scene in front of Dorothy's house when she and Jerry are talking, Dorothy tells Jerry "I'm not built that way", then Jerry leans forward with his elbows on his knees with his head down. The camera shot is behind Jerry's back when Dorothy leans over and puts her hands on Jerry's head and gives him a kiss, then gets up to go in the house. But just as she kisses him and gets up, the shot changes to in front of Jerry, except now he is resting his head in his left hand, where just a second before his hands were nowhere in sight.
Continuity mistake: After the wedding, Jerry and the neighbour hold a bottle of beer and make a toast. The position of the label keeps moving around to stop from being filmed.
Visible crew/equipment: Dorothy leaves Jerry at the hotel convention and when he opens the door a big white screen used for lighting is reflected on the door. It can't be a reflection of the building, since the car is surrounded by passers-by.
Continuity mistake: There is a scene in the movie when Jerry is talking to Tidwell, and Tidwell is suppose to be putting on deodorant but the deodorant never touches his armpits. He just passes the deodorant over his armpits as if he were really putting it on.
Continuity mistake: When he gets a punch in the eye and has a scar from it, Dorothy puts something on it, but the next day he has no scar.