Continuity mistake: At the beginning of the movie, when Clark is driving down the street looking at the map, there are 4 kids roller blading in the street. In one shot, one of the kids jumps onto a parkway lawn to avoid being hit by Clark's bad driving. Next shot, when they pan back to the kids, all 4 are still on the street.
Continuity mistake: In the first breakfast scene the ketchup bottle located between Clark and Rusty moves and at times vanishes between shots.
Visible crew/equipment: At the beginning of the movie when Clark is entering his house and the camera angle is from inside, just as he opens the door there is something red on his front porch. If you look at any of the previous scenes, that red thing isn't there. It's the bottom of a sunscreen being used to block the bright sunlight (which would have flooded the camera) behind Clark as he enters the house.
Other mistake: Most evident in the massage scene, Jilly's gold ID bracelet on his left wrist is inscribed with the name "Jerry". Jilly is played by Jerry Weintraub.
Deliberate mistake: After checking-in at the Mirage, Clark is sitting by his hotel room window admiring the northward view of the strip. Based on the view he must actually be sitting at the nearby Treasure Island hotel.
Continuity mistake: Clark gives the blackjack dealer $200 and asks for chips. Even though the dealer never give him any chips, in the next shot we see he has chips in front of him and he's already placed one in the bet area. In the next shot the dealer asks him to place his bet and we see that the amount of $5 and $25 chips in his stack far exceeds $200.
Continuity mistake: When Eddie and Clark are at the buffet, the cook has the two pots of chicken and beef, but the signs are in the wrong place. So he picks up the chicken and places it in the spot where it is supposed to go. He is about to put down the beef sign where it's supposed to go, and you see him pick up the chicken sign AGAIN and place it in the right spot, as well as the other sign.
Factual error: The club where Vicky works is advertised as being located on the strip but is actually on Paradise Rd. across from Hard Rock.
Audio problem: When the whole family is at the Siegfried and Roy show Clark is asked to participate and they make him disappear and he doesn?t come back. At one point Rusty says "I wonder where Dad went" and Ellen responds with "I don't have a clue". If you read Ellen?s lips she is actually saying "I don?t know" and waves her hands.
Continuity mistake: In the scene after Clark cashes a check to go to the card table Eddie orders a blue drink in a large glass. In the next shot when they walk away from the table Eddie's drink magically turns green. Then in the scene where they meet Wayne Newton, Eddie's drink is blue again.
Continuity mistake: When Clark and Eddie go to the casino to get all Clark's money back, they walk up to the table and there is already a folded twenty dollar bill there. Then it shows Clark puting twenty down the same way.
Continuity mistake: When Rusty Griswold first gets his fake ID, he walks in to the Riviera Casino and goes up to the bar. When he tries to order a drink, the bartender asks for ID, right when he is doing this, he lays down a napkin, and then the scene switches and he lays the same napkin down in the same place again.
Continuity mistake: In the Keno scene, after Ellen fills out the Keno card, she gets up and walks to a counter to turn in the card. While that is happening, Clark has a conversation with Mr. Ellis. During close-ups of Clark during the conversation, Ellen's shoulder and the shiny sequined dress she is wearing can be seen next to Clark. Ellen is there one moment, gone the next, back again and then Ellen is shown returning from the counter to her seat.
Visible crew/equipment: When Clark asks for Audrey and Russ at the door, there's a production member reflected in the mirror behind Clark, right before he walks in front of the television to watch the commercials.
Deliberate mistake: In the final scene when the four cars are driving away there is a road sign that shows how many miles it is to Chicago (where the main characters are from). In reality there would not be such a sign because there is not one direct route from Vegas to Chicago. A typical road sign would show the nearest cities.