Factual error: In the first scene of the movie, a diver is underwater, and he is talking to someone on the radio. How can he talk, when he is biting down on the mouthpiece from his scuba tanks? And his mouth is obviously not moving. (00:00:40)
Continuity mistake: In the very beginning, when the scuba diver is trying to open the chest and gets hit with the pipe, at first the pipe is held by a rope near the middle and when it's lowered into the water it is held by a chain at each end. After it hits the guy and is let go from the chains they are wrapped around three times. (00:01:00)
Continuity mistake: When Stanley is trying to get in the club, Dorian tells the bouncer to "lose him". The line is immediately repeated due to an editing screw up. (00:10:51)
Continuity mistake: After Stanley found the mask and gets back home and is watching some cartoons, Milo wants him to throw the frisbee. When the camera is switching from Stanley to Milo and then back to Stanley again you'll see the remote move to the right. (00:15:45)
Continuity mistake: While in Mrs. Peenmans' hall, just before she shoots him, his hands switch places on the mallet. In the first shot, his left hand is on the bottom, right hand is on the top. In the other two shots, it is vice-versa. (00:18:15)
Continuity mistake: When Stanley Ipkiss first appears as the Mask, after having jumped through the end of hall apartment window with Mrs. Peenman shooting at him, he is approached by several thugs, one of which asks him the time. The thugs begin chasing him down the alley. The thug with the beard and baseball cap at the beginning of this chase is shirtless. Halfway through the chase he now has a flannel shirt on which is unbuttoned, (visible when he jumps over a barrel as it flies open). As he stops, now the flannel shirt is buttoned up to the very top button. The entire chase scene is 4-5 seconds long. (00:19:45)
Revealing mistake: When the mask blows the small horn at the car, just before the windows blow out, you see the dummy in the car. (00:20:08)
Continuity mistake: When The Mask is making balloon animals, one gang member switches position between shots, shifting to the side of the gang leader to behind him. (00:21:26)
Revealing mistake: When the super-stretch limo is pulling up to the club, we see window after window go by, then the picture cuts for a moment to the crowd watching. Upon returning to the limo shot, the edge of the front door can be seen on the left side of the screen, ruining the illusion of the ridiculously long limo. (00:36:50)
Continuity mistake: When Stanley is doing the Cuban dance watch his legs. Whenever the camera is behind him you can see him wearing black kneepads but when the camera is in front they aren't there. (00:58:20)
Continuity mistake: During the musical number "Cuban Pete", Jim Carrey's blue shirt is sometimes tucked in and sometimes is not. (00:58:20)
Continuity mistake: When Dorian puts on the mask for the first time, right before all the smoke starts reducing, pay close attention to his goons. Some of them change position. (Clearly those were two takes pasted together, one with Dorian without the mask, and one with.) (01:04:25)
Continuity mistake: When Tina goes to the jail and meet Stanley they almost kiss for the first time. She is wearing bright red lipstick. A few minutes later she is running down an alley outside of the prison from Dorian. She is wearing soft pink lipstick. (01:09:00)
Continuity mistake: When Stanley is in jail, he put toilet papers on the toilet seat. But a few seconds later the toilet paper is not on the toilet. (01:10:35 - 01:13:10)
Revealing mistake: When Milo is trying to jump up to the jail cell, the brick wall is not brick but plastic as can be heard from his paws scratching on it. (01:11:35)
Audio problem: In the scene where Milo jumps at the cell window to save Ipkiss, Stanley says "good boy," but his mouth doesn't move. (01:13:00)
Revealing mistake: When Ipkiss is in jail and he is summoning Milo, the dog jumps up through the bars. When Ipkiss pulls him through, one of the bars swings a little bit. It must not have been a very secure cell. (01:13:00)
Continuity mistake: When Stanley and Kalloway leave the police station, there are 2 men to the right shaking hands, then they walk off. The next shot is of Doyle saying "pig Latin", and the 2 men are doing exactly the same thing again. (01:15:50)
Continuity mistake: When Dorian arrives at the Coco Bongo Club at the end of the movie, he smashes the doors which end up on the floor, but when the fight is over and everybody is leaving the club, the doors are back on the doorframe. (01:17:20 - 01:28:05)
Continuity mistake: When Dorian, as The Mask, breaks down the doors of the Coco Bongo, you see the door topple onto the doorman on the left. When the camera cuts back, he is on top of the door. (01:17:25)