!!TV serials

* HeyItsThatGuy:
** [[Series/DoctorWho The Master]] as a journalist and [[Series/SteptoeAndSon Alfred Steptoe]] as a hobo in ''Quatermass II'' (TV version).
** The 2005 remake featured a pre-''[[Series/DoctorWho Who]]'' Creator/DavidTennant as Dr. Briscoe, [[Series/{{Rome}} Indira Varma]] as Judith Carroon, and Creator/MarkGatiss as Paterson.
* MissingEpisode: Most of the TV version of ''The Quatermass Experiment'' is missing, because it was performed live in the days before any reliable method of recording television programs existed; only the first two episodes remain, in dodgy copies made with an experimental technology (the later two serials are preserved in full, though in ''Quatermass II'' the quality is still inferior).
* TheOtherDarrin: Each of the five serials[[note]]The four TV serials, and the radio serial[[/note]] features a different actor as Quatermass. The original actor died, and every subsequent actor proved unavailable after completing one installment.

!!Films
* AccidentallyAccurate: In ''Quatermass and the Pit'' (1967), the protagonists uncover remains of primitive humans from five million years ago. The characters state that no such remains have ever been found back that far in time before. In 1974, Lucy would be found and she would be the oldest human/hominid remains at 3.2 million years until even earlier specimens were found, making the concept of humans being in existence five million years ago well within possibility.
* DisownedAdaptation: Nigel Kneale was not impressed with the first two films, due to the casting of the American Brian Donleavy as Quatermass and to the rewrite of the ending of the first film to [[ViolenceReallyIsTheAnswer the army just blowing the monster up]].
* ExecutiveMeddling: American Brian Donlevy was cast as Quatermass in the first two films so they could be sold easier in the American market.
* HeyItsThatGuy:
** [[Series/DixonOfDockGreen George Dixon]] and [[UpstairsDownstairs Hudson the Butler]] in ''The Quatermas Xperiment'' (film version).
** [[Franchise/CarryOn Sid James]] in ''Quatermass 2'' (film version).
** [[Film/IndianaJonesAndTheLastCrusade Walter Donovan]] as Colonel Breen and [[Series/BlakesSeven Roj Blake]] turn up in ''Quatermass and the Pit'' (film version).
* TheOtherDarrin: Not quite as bad as the serials, but the length of time between the two fifties films and 1967's ''Quatermass and the Pit'' meant Brian Donlevy was replaced by Andrew Keir. In other words, Quatermass changes from a scowling American to a fiery Scot. Astonishingly, it works.