Continuity mistake: At court, Carlito introduces his lawyer to the judge. The lawyer takes his hand away from his chin. Then in the close-up his hand is back and he removes it again.
Other mistake: In the boat scene when Kleinfeld says: "Oh, I see the buoy!", the actor playing Frankie has hard time not bursting into laughter. Sean Penn seems to poke him in the back as well.
Continuity mistake: In the party scene at Dave's house when Dave is yelling at a guest for having sex outside, the shot of Dave and Carlito appears to be around sunset, but, when the shot switches to the guest, the shadows appear to be more like noon.
Factual error: In the scene where Carlito goes behind the bar to get his money from the box under the register, when the box is open both 100 bills have Ulysses S. Grant on the front, not Benjamin Franklin.
Continuity mistake: When Carlito and his girlfriend are having coffee early on in the movie, a cigarette appears and reappears in her hand throughout the scene.