Revealing mistake: When Anguirus makes his sacrificial charge against Gigan, the hand that is moving the Anguirus costume can be seen holding it.
Continuity mistake: When Louise is in the study, sunlight is coming through the manor house windows, even though it's supposed to be nighttime.
Other mistake: It makes no sense that the pimp would die from having the tip of his tongue bitten off. (00:23:35)
Continuity mistake: When Abel rams the sheriff's car, he is driving a 1966 Chevrolet. He leaves and ends up at the veterinary clinic, where the doctor injects him with a poison. During the following chase, Abel's car becomes a 1967 Chevrolet, then reverts back to the '66 Chevy.
Continuity mistake: At the beginning of the movie, Bruce Lee enters a restaurant in the Rome airport and, because he can't read the menu nor speak the language, he accidentally orders five bowls of Campbell's Soup. When the waitress first delivers the five bowls, the soups are very different colors than they are in subsequent close-ups. Disappointed but hungry, Bruce plows into the soup. Ten sequential close-up shots show him dipping his spoon into bright red, tomato-based soups; but, by the time the spoon reaches his mouth, the spoon is dripping creamy white soup, every time.
Continuity mistake: Pickett Smith has his shirt sleeves rolled up at the movie's beginning, then they're rolled down and buttoned then rolled back up before his canoe gets knocked over.
Revealing mistake: After the attack on the village by the three assassins, Itto places his son in bed next to his dead wife Azami, and in the close-up shot of them you can see Azami swallowing. (00:17:26)
Continuity mistake: While Prince Mamuwalde struggles with Count Dracula's goons, some candles are knocked off a candelabra, but the next shot shows the candelabra with the full complement of candles it had before the fight.
Revealing mistake: During the flashback sequence when Gunbei's double is decapitated, his severed head hits the floor but you can see that the actor's head is still inside his clothing. His top has been pulled over his head to make it look like his head has been cut off. It's even more obvious in the wider shot right after. (00:27:42)
Other mistake: The movie opens with a quote from Lewis Carroll, mistakenly credited as Carrol with just one L.
Character mistake: During the monopoly game, Peppermint Patty rolls a 12 on the dice but only moves 7 squares.
Revealing mistake: The protagonist jumps from a bridge and boards the train to try to save the Professor. When he is walking on the top of the carriages, look at the treetops in the background; the train is stationary. (00:12:00)
Continuity mistake: When Woody enters the café and sits at the table, Miss Meanie pours him a glass of water. The glass disappears in the next shot.
Continuity mistake: When Mr. Kumagoro visits the Uncle at the hospital, he drops a package on him; the niece looks at him startled, her arms crossed in a different position between shots.
Other mistake: The opening credits misspell the name of production supervisor Peter Sczygiol ('Sceygiol') and firearms technician Gino Vagniluca ('Vigniluca').
Other mistake: When the wrapped body parts are going for the mistress (the one telling the story), you can see the right arm dragging itself across the floor. However, the arm that grabs her face from above is also a right hand. How did the murdered wife have two right arms?