At the double wedding we see that behind Mr Bingley, Miss Bingley and Georgiana are seated with at least one person between them. However, when the camera is on them, they are standing very close together. Also, just before this shot, Miss Bingley turns her head as if to speak to someone, but is facing forward in the closer shot.
Although Mr. Bennet declares that, "Mr. and Mrs. Wickham will never be welcome to Longbourn," following his daughter's scandalous elopement and patched-up marriage, the very next scene shows them being welcomed to Longbourn. The novel explains this as being due to the arguments of Elizabeth and Jane on behalf of their sister, but the movie does not.
When Lady Catherine de Bourgh pays her visit to Longbourn, Hill announces her and stands with her back to the door. In the next shot, Hill is beside the door and, in the next shot, is once again standing with her back to the door.
When Elizabeth blows out the candle in her room after Wickham and Lydia have left Longbourn, the room goes pitch black. However, a roaring fire is seen in the grate just behind Elizabeth, so the room would not have gone pitch black.
In the final scene after the double wedding, when they walk through the bough that Kitty & Maria are holding, some of it falls into Elizabeth's dress and sits on her bust for the rest of the scene.
At the very end when Darcy means in to kiss Elizabeth, there is a very visible makeup line that shows the makeup artist didn't put makeup on his neck (most likely to avoid getting makeup on the collar of his shirt), as a result when it pauses at the end, it is a very noticeable error.
During the double wedding, the vicar says that marriage is not to be "enterprised" lightly. While we often use the word enterprise as a verb nowadays, it is, strictly speaking, a noun and certainly was never used as a verb before the twentieth century.