The location footage in this film, especially the various animals, was re-used as stock footage for dozens of films in the fifties and later, including Tarzan, the Ape Man (1959), Watusi (1959) and the 1973 version of Trader Horn (1973).
The movie has no music score whatever. The only thing at all musical in the film is some African chanting and drums.
Errol Flynn was originally cast as Quartermain, but turned it down, as he did not desire to sleep in a tent on location in Africa. Instead he did Kim (1950), which was filmed in India, but the accommodations for the actors were at a local resort.
The scene in which Deborah Kerr cuts her own hair and then cuts to her sunning with a perfectly quaffed hairstyle got such a big laugh at the initial screenings of the film that producers debated removing the scene. However, they couldn't figure out another way to explain Kerr's change of hairstyle, so they kept the improbable scenes intact.