Goofs

When the alien's gas regulator begins to malfunction when he first confronts Lawrence and Elliott, he tries to turn the knob on his suit while standing up. But the close-up of him trying to turn the knob is an insert shot of a scene late in the film, when he is lying on the ground and again attempting to turn the knob back on.

Enid's description of the spaceship as "...a glass ball with three metal bands around it..." is nothing like the spaceship miniature or full-size mock-up.

Enid's car had a blow out on the night it failed. When John Lawrence went back, he simply took a small air pump and pumped the tire up, and went on about his way. When a tire blows out, it destroys the tire. At the very least it would require patching before it could hold air. And in most cases, the blowout is the result of a catastrophic failure of the tire. And once the tire fails, even more damage is done to the tire before the car can be brought to a stop. The damage gets worse because you drive on the flattened tire, and the rim damages the tire.

Tammie the Police Constable is not wearing a standard British police uniform of helmet, jacket with police buttons, epaulets with his official number on them, belt, and truncheon. Instead, he's costumed in a ex-military dress jacket and a flat sailor's hat. As such, he would have no legal powers to initiate a search or investigation, as a constable only has authority when in uniform.

While enlightening John on American and British synonyms, Enid talks about what to "say in England," but she should have said Scotland,

When Dr. Mears tries to overcome the alien by shutting off his breathing apparatus, you can see the circular hole in the top of the aliens helmet enabling the actor Pat Goldin to breath.

The background of the Scottish village is obviously painted on a flat canvas.

In a subtitled edition, when John arrives in Scotland, the sailor's greeting contains the note "British accent," but the man's accent is very Scottish. While Scotland is part of Britain, the subtitle should simply have said "Scottish accent" for clarity.

As John and Enid first arrive at the front door of the Broch, the boom mic shadow shows up on the stones right above the front door as they walk towards it.