After Dennis Price (Francis) locks her bedroom door, Anne Crawford (Oriana) shoves a chair under the door handle. However, in doing so, the door moves back into the door frame as though it was not locked.
Towards the end of the film, a guitar can be heard playing part of 'Concierto de Aranjuez' a classical guitar concerto by the Spanish composer Joaquín Rodrigo. However, it was not composed until 1939.
The building wall 'bends' each time Stewart Granger (Richard) rams the second assailant of Gerard Heinz (as Gerard Hinze) (Don Carlos) against the 'solid' wall.
Don Carlos has a German accent.