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.
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.
Continuity mistake: When the Griswolds get into their hotel they meet their parents at the intersecting door Audrey is pictured by the door frame but the camera cuts off and she is sitting on the bed.
Continuity mistake: At the beginning of the movie after Clark trips on the bike, you can see Clark put the Vegas brochure in his jacket pocket. When he goes to open the front door you can see no brochure in his left hand. In the next scene when he enters the house the brochure is back in his left hand along with his briefcase. (00:01:39)
Continuity mistake: Eddie (Quaid) takes Clark (Chase) to the casino buffet for dinner. As they fill their dish with food, Clark tells the server behind the buffet table that the chicken and beef dishes are labelled incorrectly. The server then switches the tags, placing them in each dish. In the next scene he repeats the switch.
Visible crew/equipment: The camera and the cameraman are reflected in the chrome of the Griswold limousine when they are driving down the strip.
Continuity mistake: In addition to the submission regarding the tour van acquiring damage to the hood after crashing through Wayne Newton's house, the mirror on the drivers side is bent. In the next shot when Clark exit's the vehicle and closes the door, the mirror is gone.
Continuity mistake: At Hoover Dam, Clark pulls out a small rock and causes a little leak. While he's fixing, it another develops. He puts his left side against the second leak to hold it until he gets the gum in the hole. The water stain on his shirt changes from his left side to his right side, then eventually his entire shirt, in different shots.
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.
Continuity mistake: In continuity of Rusty's fake ID lacking the Vegas background, both his right and left hand are covering significant parts of the text in the oversized ID he is holding which doesn't appear in the copy of the ID.
Continuity mistake: When Russ takes his fake ID picture on the street, and he sticks his head in the giant license and there is no backdrop behind his head...you see Vegas light behind him.. but when the casino guy checks the fake ID, it is all white behind his head... no Vegas lights.
Visible crew/equipment: In the beginning of the movie after Clark trips over the bicycle in his driveway and approaches his house you can see the microphone in the upper middle of the screen momentarily.