Goofs

When hurrying to the phone in the Pressure Control Block, McLeod puts down his jacket, which slips to the floor. It appears to have returned to where he originally placed it when he retrieves it in another shot, however.

In London, when the inspection tour guide has closed the door of the second Rolls Royce, a lorry is just about to pass by, but in the next shot it has become a bus.

At 54:50 in, Shiela the barmaid handles the stone and lays it down. It then splits open with a crack (which would cause a burn) Her neck is undamaged. In the cut scene, the reporter (Sid James) says "Look at her neck", which she takes her hand away from, revealing a burn mark, which wasn't there before.

At Winnerden Flats, when Quatermass is being escorted to his car, a guard, who has turned the car around, can be seen in the driver's seat. In the following shot, when you would expect the driver to get out and make way for Quatermass, another guard comes from the right and opens the driver's door to an empty car.

When Quatermass pulls up at the traffic lights in London, a car to his left does likewise, but this car is not seen in the following close up of Quatermass at the wheel.

After the opening paragraph of the newspaper report detailing Vincent Broadhead's purported emergency Middle East trade mission, the remainder of the piece details postal voting in badly-formed columns; similarly the accompanying texts about King Leopold and Big Ben bear no relation to their headlines.

The sentry run over by Quatermass and Lomax is clearly a lightweight dummy in long-shot.

The guards in the refinery are seen using American-made Thompson sub-machine guns but during that period in Britain they were far more likely to have used British-made Sten Guns or Stirling-Patchett sub-machine guns.

The film makes out that the fictional area of Winnerden Flats is on the way to Carlisle and about a 90 mile drive from the rocket base yet Quatermass keeps driving back and forth between the London and Winnerden Flats. In actuality if the drive had been the rocket base and Winnderden flats had been 90 miles then this would have put the rocket base either in central Lancashire, North Yorkshire or north of Edinburgh or Glasgow (depending if Quatermass was driving north , south or from the east). Therefore his constant drives to London would have been somewhere between 250 - 340 miles, or 4.5 to 7 hours from London (maybe even longer on the 1950s road network) yet in the film he's able to go from London to the factory inspection and get back to London and not only is it still daylight but people are still at work on his return.

Quatermass and Marsh are seen supposedly driving north on the Carlisle road and just about to turn left. Yet earlier in the film Quatermass is shown on the same road, also driving north (from London) but in the opposite direction.

Brand plots the location of the objects falling 90/100 miles to the north but, for the apparent scale of the map he is using, his compass setting is much too small and would produce a radius of perhaps 10 miles at the most.

When Quatermass is escaping from the secret plant the guards open fire with their machine guns. Given the amount of chemical tanks and pipes running through the plant, firing weapons, especially machine guns would be extremely dangerous.