Revealing mistake: Near the end of the film, when the people are in the house fighting the Leprechaun, one of the characters is using a shotgun. The Leprechaun rides up and down a hallway on a skateboard and the character with the shotgun shoots at him, missing not only the Leprechaun, but everything else as well. Unless he was using a round full of confetti that I've never heard of, he should be shooting the wall and everything else in sight, yet nothing at all is hit.
Continuity mistake: Officer Tripet gets tired of running and he slumps down against a tree. His places his left arm up on the trunk and it slides down so that now his hand is down atop his knee. The shot changes to his front and now the hand and arm are back up on the tree trunk above his shoulder.
Revealing mistake: When Tori and others are fighting the leprechaun in the kitchen the wall phone rings and she picks up the hand set. It's the leprechaun on the line and in fear and anger, she slams the hand set back in place and tears the entire phone off the wall. As the phone rips away, it's obvious there is no phone line connector on the wall, only a nail the phone was hanging on.
Continuity mistake: After Ozzie and Alex leave the gold coin to be examined, when the shop owner looks through the book the back clasp of his suspenders is unclasped, then is clasped when he's at the stairs, only to be unclasped after he moves the tricycle, then clasped yet again.
Visible crew/equipment: The Leprechaun is on roller skates heading towards the white picket fence. As he gets close while the shot is over his shoulder, his shadow is cast on to the fence at the left edge of the screen. Problem is, a crew members shadow is right next to him for a split second right before the camera angle changes and he smashes into the fence.
Visible crew/equipment: When the shop owner looks through the book for information about the gold coin, he hears the bike bell and when he walks toward the stairs, the crew's solid brown rug is visible on the blue floor - note its edges in front of the white bookcase. It is also seen when he walks back to the safe the second time. That rug is gone in all other shots. (This has nothing to do with the large patterned Asian-style area rug.)