Goofs

During the operation scene, Vulnavia is seen cutting a hole in the painted backdrop through the face of a seated man. Inspector Trout and Tom are subsequently seen putting their heads through two slashes in the backdrop, one of which is located above this hole. But after Vulnavia's death, as Trout orders his police constables to search the house, the holes for their heads have disappeared.

After Vulnavia dances with Phibes, he lowers the cage of bats into the cellar. Vulnavia runs up the stairs, then appears downstairs seconds later in different clothes.

During the operation, Vulnavia attacks a painted backdrop with an axe. She is shown alternating between being in front of it and behind it in quick succession.

When Dr. Hargreaves fights against the frog mask, he is seen trying to open the catch with his hands, but in all the close-up shots of the ticking catch, there are no hands in sight.

When Vulnavia is wrecking Phibes' lair in the film, she knocks the bass drum off the bandstand on to the dance floor. Later, when Trout, Crow and Vesalius approach the organ, the drum is nowhere to be seen.

The bats seen in the film's first murder are fruit bats. They would never eat flesh. They eat fruits or lick nectar from flowers.

The 10 Plagues of Egypt are wrongly depicted both in order of appearance and what they actually were. According to the book of Exodus, the 10 Plagues were: 1. Water to blood, 2. Frogs, 3. Gnats, 4. Flies, 5. Pestilence (upon the beasts of Egypt), 6. Boils, 7. Hail, 8. Locusts, 9. Darkness, and 10. Death of the Firstborn (Exodus 7:14 - 12:36). The correct names are written in Hebrew, but the rabbi reads "pestilence" as "bats" and "gnats" as "rats". The first and second plagues on the scroll are moved down to be the fifth and sixth plagues. Finally, the rabbi incorrectly reads the plagues from left to right instead of right to left as is normal for Hebrew, thus changing the order of the plagues even more so.

When Dr. Phibes spills the green syrup over the sleeping Nurse Allen, he accidentally covers the light and the glass on the nightstand. Later the nurse is completely covered in syrup, but the light and the glass are perfectly clean.

The head of the sleeping Nurse Allen gets completely covered with thick green syrup, leaving her unable to breathe. Even if she took a sleeping pill she would at least unconsciously stir or even wake up, yet she lies perfectly still and is probably long since suffocated even before the locusts arrive.

The chessboard is set up incorrectly. Each player should have a white square to his lower right, but during the game those squares are black.

Virginia North smiles broadly as she dances with Vincent Price. Her face is concealed most of the time, but if you look closely, you can see her face for a moment and she is clearly trying not to laugh at Price's deliberately campy performance.

One can clearly see wires attached to one of the flying bats.

The amount of bats that killed Dr. Dunwoody in the film could never have come from the small cage that was lowered into his bedroom.

When Dr. Phibes calls the chief surgeon the second time, it is revealed that the jack port on his side of the neck is fake, as it has a support bar wrapped around the neck in order to maintain position.

When Dr. Phibes is drizzling the green syrup on Nurse Allen's head, actress Susan Travers is visibly flinching and forcing her eyes to remain closed as the goo lands on her.

Dr. Phibes' Clockwork Wizards play "One For My Baby and One More For the Road," sung by a Frank Sinatra imitator. The song was written in 1943; Sinatra recorded it in 1947.

Using neither club nor injection needle, Phibes seems to render the chauffeur unconscious (for hours) with a Vulcan nerve pinch from Star Trek.

Seconds after Dr. Kitaj arrives at the London Aeroplane Club, contrails appear over the left side of the hangar roof. In the 1920s, no aircraft flew high enough to create contrails.

The song "You Stepped Out of a Dream" was not released until 1940, 15 years after this film takes place.

The film takes place in 1925. The automobiles, airplane, and film projector seem to be from the 1920s, but the house interiors, including the lights around Dr. Phibes' organ, and clothing appear to be early 1970s "mod" style. At the end of the film, Dr. Phibes plays "Somewhere Over The Rainbow", which was written in 1935.

When he plays the organ in the film, Dr. Phibes' hand movements almost never match the music that is heard.

In the shot in the film where the car chases the plane before takeoff, you can see the shadows of the camera and cameraman.

Trying to remove Dr. Whitcombe from the solid wooden wall, the police turn the unicorn head with its spiral horn in the wrong direction, essentially screwing Dr. Whitcombe tighter to the wall rather than loosening him from it.

At no time in the film do the authorities consider that there are 10 curses, but only nine surgical team members to target.

In the film, Dr. Phibes' face is disfigured so badly that he cannot open his mouth anymore and, instead, uses a gullet opening at his neck to eat; however, since he cannot chew, he should not be able to eat any solid food, yet he does so in the film.

At the mausoleum, Trout and Vesalius find ashes in Phibes' coffin, and Trout suggests that they belong to the chauffeur. If Phibes had a chauffeur, why did no one ever notice that he disappeared without a trace after the crash.