Continuity mistake: In the scene where Becky is talking to Steyne on the balcony of his house just after she has performed in the masque for his guests, she still has quite a quantity of black eye make-up visible under and around her eyes. In the next scene, just after they step back inside, it's gone.
Factual error: When Joseph Sedley presents Becky Sharp with the parrot, he says it is because she loves all things that come from India. The Blue and Gold Macaw, however, is native to South America. (The director's commentary makes it clear that she is aware of this. (She could hardly not be, coming from India.) It was a bit of "poetic license.")
Continuity mistake: Towards the end of the film, when Becky and Rawdon are eating dinner in their house, Rawdon throws the napkin that is tucked into his collar on the table. In the next shot the napkin is back in his collar, then when he stands to leave the napkin is back on the table.