The original BBC serials were not shown on American television. As a result "Quatermass" was unknown to potential U.S. audiences. As was done with the previous two movie adaptations, the title was changed. Twentieth Century Fox released this in the United States as "Five Million Years to Earth" (1967).
In the London Underground, there are quite a few posters from other Hammer projects such as Das schwarze Reptil (1966), Blut für Dracula (1966), and Der Teufel tanzt um Mitternacht (1966), as well as My Fair Lady (1964) and Das Hotel (1967), on the station walls. An old, partially-ripped poster for ...und ledige Mädchen (1964) can be seen on the wall opposite the entrance to Hobbs End station.
Director Roy Ward Baker subsequently looked back on the film as one of the happiest shoots of his career.
When Dr. Quatermass is picking at the eyeball of the dead Martian creature in his laboratory, the pupils of the compound eye are a rectangular slot shape rather then round like a human eye. This is reminiscent of a goat's eye, a creature that, for centuries, has been associated with witchcraft and sorcery.
Of the three Hammer "Quatermass" films, this is the only one which "Quatermass" creator Nigel Kneale personally liked. This was largely due to the fact that he was much happier with Andrew Keir's performance as the title character than he had been with Brian Donlevy's in Schock - The Quatermass Xperiment (1955) and Feinde aus dem Nichts - Quatermass 2 (1957). He described Donlevy as "a former Hollywood heavy gone to seed" and claimed that he was drunk during much of the shooting of the latter film, a claim which its director Val Guest repudiated.