'Marshall Jones'' character is referred to in the credits as Konratz. However, all the characters refer to him as Konrad.
Peter Sallis' character (the man seen shaving in the circular mirror after the guard lets Marshall Jones through customs) is named Schweitz in the credits. However, on two occasions, this character is referred to as Sallis, by both Marshall Jones who refers to him as "Captain Sallis" and by Peter Cushing who refers to "Sallis'" death.
The car chase is full of errors in continuity. The action switches back and forth from a single lane road to a double lane highway and at one point Keith overtakes a blue car ahead of him in the road to the right and the police car follows. A few shots later, Keith overtakes a brown car and the scene cuts to Supt. Bellaver saying, "All right, let's take him." We then cut to one of the two cars overtaking the blue car and not the brown one.
In the chase, Supt. Bellaver's hair is sticking up in one shot and smoothed down in the next.
When Michael Gothard is finally apprehended, his left arm is curled up behind his head in one shot and then disappears altogether in the next.
When Keith escapes from the police, after he has severed off his own hand, he jumps over a short fence/style and rolls on the grass on his landing. Using pause you can see his real hand come out of his cuff just as where his stump should be
The "dead composite" that Dr. Browning is going to operate on moves her feet when she is placed on the operating table.
The security camera footage is obviously not filmed by an actual security camera, as the image pans, zooms and cuts.
Near the end of the film, Vincent Price throws "Konratz" across the lab. A stuntman with different colored hair takes the actual fall, then the editor cuts back to the real Konratz.
Foley: the footsteps of the characters are very hard and sharp, even when they're walking on carpet.
During the club scenes, the singer's lips never match the song he's supposed to be singing.
When Dr Sorel is told by Bellaver that the case is closed, he says the word "Garbage!". However, his lips mouth the word "Crap!" (This is from the VHS version)