Continuity mistake: When Frank returns home from the Lynskeys, he parks his Volvo right beside the outdoor fuse box post, with the box facing beyond the trunk of the car. However, after Frank goes upstairs, in the next exterior aerial shot the Volvo is 10-15 ft. away from the fuse box post and the box now faces beyond the front of the car. (00:17:30 - 00:19:20)
Revealing mistake: As the three babies fly towards Mrs. Waterhouse, when they land on her it is blatantly apparent that they're merely three dolls in this shot. She actually grips two from behind and the center doll is attached to her as she moves backwards. Also, in the shot facing the babies the center baby is in the bouncer seat with the rod attachment overhead, yet, in the shot facing Mrs. Waterhouse the rod attachment is gone. (00:23:50)
Continuity mistake: After Frank destroys Ray's fence, he backs the car over Budzo (the ceramic little gnome), crushing it on the lawn. Yet, when Ray picks him up crying out, "Oh, my Budzo! My Budzo!" he is holding the gnome's uncrushed head! (00:07:05)
Continuity mistake: At Frank's house, while Stuart rambles on about happy and productive ghosts, Frank pours himself a bowl of Jeepers Creepers yellowish color flake cereal. After Frank sprays Stuart in the face with the Shoo Fly, Frank eats cereal that are roundish dark-colored bits. (00:19:35)
Continuity mistake: The colours on the dial of the freezer Frank goes in changes between shots. When Lucy turns it down you can see the colours are light and dark blue. Later on in the wider shots and when she tries to open the door and Milton Dammers stops her, you can see it's blue and red.
Other mistake: When Frank first runs into Ray's ghost on the street, and they duck into an alleyway to talk, Ray accidentally calls Frank (Michael J. Fox) by his real name "Mike" instead of his character name "Frank." Ray says "I felt this vise-like grip squeezing my heart, and I couldn't breathe, Mike."
Continuity mistake: At the police station, when Dammers tells Lucy about the day that Debra died, there is a shot of the utility knife in Frank's toolbox and the initials F.B. are written in white on the knife. Later, when Lucy finds Frank's utility knife in Mrs. Bradley's bedroom, the initials are written differently. (00:44:30 - 01:05:50)