Visible crew/equipment: Towards the beginning of the movie when Ralphie's dad is in the basement fixing the furnace and the entire family is staring at the door, you need to keep an eye on the left side of the screen. There is a crewmember in the family room, who is on the screen by mistake. You don't see the person right away, but it is in that sequence when you see the mom in the shot, then you can see the leg of the person very quickly in the background.
Continuity mistake: When the "old man" first puts the lamp on the edge of the box there is no light fixture on which to place the shade. He then returns the lamp to the box and when he brings it out, there is a place to put the shade. Also as he hands it to the mother and then takes it back to put it on the table, there is no electrical cord visible. However, just before he sets it down on the table you can see a cord in his left hand.
Continuity mistake: In the kitchen scene, as Ralphie's father comes in for hot water to thaw the car, and then turns his attention to the furnace, there is a white funnel on the shelf beneath the clock. The camera follows him to the basement steps and the smoke coming from the register. In the next shot, showing the anxious family, Ralphie's mother moves forward and the funnel has moved to the sink behind Ralphie's head.
Continuity mistake: When the father comes in for hot water for the car, the furnace goes haywire and black smoke comes out of the register. The father goes to the basement to fix the furnace and yells upstairs for somebody to open the damper. The mother goes over and begins to move the bottom lever and then changes her mind and moves the top lever all the way to the left. In the next shot the top lever is all the way to the right while the bottom lever has miraculously moved all the way to the left.
Continuity mistake: Early in the movie when Ralphie catches up with Flick on the way to school, Ralphie is holding a book or folder that has the top left corner folded over. In the next shot when Schwartz joins them, the fold is now on the bottom left side. Ralphie's arm covers the top corner of the book most of the time so look closely during the last few seconds of the scene.
Other mistake: When Ralphie and Flick are walking to school for the first time, they meet up with Schwartz, coming down the steps of his house which appears to be two houses down from Ralphie's. Later, when Ralphie is lying in bed after the soap in the mouth scene, the narrator (older Ralphie), states how "Three blocks away, Schwartz was getting his."Rob Meears
Continuity mistake: In the playground scene when Flick first sticks his tongue to the flagpole, the street in the background has been snowplowed. The kids all go back in to the classroom without Flick. When the teacher asks "Where's Flick?", and looks out the window and sees him at the pole, the same street in the back ground has not been plowed.