Revealing mistake: As Roney opens a drawer in a filing cabinet, a blue case and a wallet folder appear on top of the cabinet, that were not there in a previous shot. (00:21:25)
Continuity mistake: When the police sergeant, Quatermass and Barbara exit the station entrance to look at he derelict houses, at the moment he says "these are the houses" Barbara is facing directly forwards with her feet together, in the next shot as she replies " they really are derelict" she has turned left towards Quatermass and is standing with her feet together:. (00:16:20)
Continuity mistake: When the police sergeant, Quatermass and Barbara exit the station entrance, there is sign on the left in white letters on a black background that says London Transport No Admittance that is leaning against the wall, in next shot the position of the notice has changed position and is more forward facing. (00:16:20)
Continuity mistake: As the journalist in the red coat is walking quickly down the platform to join the press conference, she is seen from behind passing a large man stepping down from the platform and onto the track. In the next shot (in front of her) in the large man has disappeared. There is no way that he could have could have been hidden out of shot because he would have been walking alongside her down the track at the same time. (00:03:20)
Visible crew/equipment: A gloved arm pulls out of the shot as Quatermass comes around the corner of Hobbs End to find a thoughtful Barbara. It is the very last scene of the film before the titles.
