Revealing: At one point when Clark is flying down the hill through snow drifts on his saucer sled after greasing it up you can see the guide wire pulling the sled.

Continuity: In an early shot of the outside of the house, the motorhome that Eddie and family show up in is parked in the driveway. The problem is, they don't appear until much later in the film.

Continuity: When the Griswold's are driving to the tree farm, they are being harassed by the rednecks in the truck.  Several shots of the front of the truck show only two passengers, but one view of the truck through its rear window shows three passengers.

Continuity: After Eddie et al arrive at the Griswolds, "Snots" is introduced. When everyone else has gone into the house, Clark is left outside with the dog. A shot shows the dog at Clark's side, and if you look at Clark's sleeve, he's wearing a sweater, but actually has on a windbreaker. At the end of the movie, Clark's wearing the sweater. Apparently the shot was taken of him and the dog, and edited back into the film early on.

Other: When the Santa Sleigh is launched in the air by the ignited sewage, the sleigh flies over the moon. Now on the DVD version of the film, it's not clearly visible, but on the VHS version, you can clearly see there's a box around the sleigh that looks like the sleigh is under a microscope slide.

Visible crew/equipment: Just before Clark goes down the hill on the saucer sled you see the view down the hill. If you look carefully at the right of the screen you can see two pinkish cables stretch into the distance. These are the pyrotechnics that make the explosions when Clark sets off. You can see it clearly on the DVD version, but not too clearly in the VHS one.

Continuity: In the scene where Clark Griswold is on a ladder putting Christmas lights up on his house the trees in the background are green and leafy, (not evergreen trees), indicating summertime, although there is snow on the ground and it is supposedly winter.

Continuity: When Clark is sliding down the hill on the sled, several times you can see fins on the bottom of the sled to help whoever was riding the sled control the direction a little better. When Clark is rubbing the oil on the bottom of the sled before he starts the sled is completely flat on the bottom.

Continuity: In the opening scene, when the family is on their way to get a Christmas tree, they get into a road rage battle. If you look closely at the shape of the headlights, the car the family is in and the stunt car are noticeably different.

Continuity: When Uncle Lewis and Aunt Bethany arrive, the wreath on the front door is lit with Christmas lights. When the door opens from inside the home, there are no lights on the wreath....it is just plain green.

Continuity: When Uncle Louis drops the match in front of where Eddie empties the "chemical toilet" if you look VERY close you can see the rope that launches him into the air.

Visible crew/equipment: In the scene where Clark gets his "Christmas bonus" he starts going off about what a lousy guy his boss is. During his outburst you can see a crew member's head pass by the bottom left corner of the screen

Other: After Eddie kidnaps Clark's boss, he drives off and if you look at the ground the snow looks like soap bubbles, because you see them waving around.

Factual error: Clark has too many lights on his house causing the city to go dark. There is a scene where the power plant needs to boost their output. There is a close-up of a guy flipping the switch. Look at the way they spelled auxiliary - auxilliary.

Visible crew/equipment: I've noticed in a couple of scenes where Chevy Chase and Beverly D'angelo are standing in the front hallway of their house: you can see the wooden rafters of the ceiling of the set in the dining room.

Continuity: When Clark is outside, trying to get the lights to work, Ellen comes out the door, pulling a sweater around her shoulders. First it is on one shoulder, then both, then one, and at the end of the scene she has it on properly, with both arms in the sleeves.

Continuity: In the scene where Clark and Eddie are standing next to the christmas tree drinking egg nog, when Eddie walks over to the decoration and knocks it over in one shot his glass is less than half full and in the next it is almost completely full and he takes a gulp.

Continuity: When the squirrel is being chased by Eddie's dog, it passes through the broken door and then vanishes.

Other: Another note about Clark's falling through the ceiling and onto his son's bed: Take note of the shot of him in the attic after falling through the ceiling. He's standing on the upper bunk of the bed now, but from the shot in the attic, he's only down to his knees or so. Assuming his home's ceiling joists are 8 inches or so, then the mattress of the upper bunk would have to be no more than, say, 10 inches from the ceiling for that much of him to still be in the attic while standing on the bed. I've never seen a bunk bed whose upper bed gave you less than a foot of space between mattress and ceiling!

Continuity: The Christmas tree is still visible after it has burnt down.