Factual error: When Ace is watching the news report about the investigation of his gaming license and crime connections, you can see the Mirage Hotel in the background of the news studio. The Mirage was not opened until late 1989, and the movie takes place well before that.
Continuity mistake: When DeNiro catches the cheats at the card tables, he takes the one with the beard to smash his hand with a hammer. In the first shot the guard is holding the cheat down by the wrist, but in the next shot the guard's hand is up by the guy's elbow.
Factual error: When Joe Pesci is driving to meet De Niro, he has to change cars. The scene right before going to the garage, they show Pesci's car driving around a corner and at the bottom right of the screen, you see a lamp post with a bus sign on it that reads CAT. CAT (Citizen's Area Transit) wasn't established in Las Vegas until late 80's early 90's. Before that it was the Las Vegas Transit. This scene was supposed to be late 70's, early 80's...
Continuity mistake: When Joe Pesci and his brother are beaten at the end, Dominick is thrown in the pit and facing one direction, after Joe Pesci is beaten and thrown on top, Dominick is facing the opposite direction than he was originally. (02:48:30)
Continuity mistake: In the scene towards the end before De Niro's car explodes, in the first shot when he opens the door its window is down as he gets in the car, but in the next shot as his motions are replayed, when he opens the door that window is all the way up, then it's down again in following shots. (02:46:00)
Continuity mistake: When De Niro catches Stone and Woods in the restaurant, De Niro takes out some money from his coat pocket and lays it on the table. In one shot the money is straight, in another it is diagonal and in the final shot before De Niro picks it up it is straight again.
Continuity mistake: When Ginger is arguing with the gambler at the craps table about "giving her a bigger cut", the man reaches for her purse to show her the chips she's been stealing from him. As she pulls the purse back, the gold chain strap breaks. The next shot of Ginger shows a repaired chain.
Audio problem: Ace yells "come with me now" over and over while dragging Ginger out of the house after overhearing her trying to have him whacked. DeNiro's lips are not moving while he's yelling.
Audio problem: When Nicky and Frank rough up one of their debtors, Frank tells him to smarten up, but his mouth doesn't move. (00:31:55)
Continuity mistake: Jennifer has the diamonds inside her hair bun and she's shaking it to retrieve the diamonds onto the table. As Santoro slaps her face as a gesture to thank her and for her not to get smart with him, her hair bun comes loose and falls out into a pony tail. The next shot then shows Jennifer with the hair bun perfectly groomed again on top of her head.
Continuity mistake: When Nicky has the guy's head in a vise, after it squirts Nicky's hair changes between shots, from neat to messed up.
Continuity mistake: Towards the end of the movie, when they first kill Nicky's brother, Dominick, and they throw him in the pit, his full chest is covered in blood, but in the aerial shot it is clean with just the bloody face.
Visible crew/equipment: When Ginger obtains the deposit box's key after having rushed to Ace's house and goes to the bank to open the deposit box, a boom mic can be seen reflected on the bank's glass door.
Continuity mistake: Before Pesci stabs the pen, DeNiro asks a guy if it's his pen. A glass on the right, inches away from the napkin where the pen was laying, appears and disappears between shots.
Continuity mistake: Before the pen-stabbed-in the neck scene Joe Pesci is talking with a guy about placing some bets. A coffee cup and saucer suddenly appear on the table after Pesci leaves the place.
Continuity mistake: When news on Robert De Niro not having a casino license first hits the airwaves, the news broadcast displays a still picture of Joe Pesci having a conversation with his friend Frankie. The picture that they use is when Pesci and Frankie have tooth picks in their mouths because they don't want FBI agents lip reading what they are saying. But that didn't happen until later on in the movie. So how could they have displayed a picture of a conversation that hadn't taken place yet?
Continuity mistake: When De Niro is proposing to Sharon Stone, the position of his head is not continuous between the front and back shots.
Factual error: We hear Ace in the voiceover talking about Ichikawa, a guest at Tangiers, and Ace says, "About a year ago, he cleaned out a couple of casinos in the Cayman Islands." There have never been casinos in the Caymans. (00:19:10)
Continuity mistake: When Ace is having a meeting with Green about him firing the cowboy, Ace stubs out his cigarette. In the next shot from behind Ace is still smoking, but when in the front he has no cigarette.
Continuity mistake: It is daylight when the car of Ace Rothstein explodes. However, it is night when he is being placed in the ambulance.
Chosen answer: In the end.