One day on set, Hayley Mills almost accidentally burned down her dressing room. After filming a scene in which her clothes became soaked, without thinking, she put a pair of wet trousers on top of an electric heater before leaving the room. If it had not been for a crew member noticing the smoke which began to billow out of the room, Mills' dressing room, and possibly part of the set itself, could have been destroyed.
Wilfrid Hyde-White replaced Charles Laughton as Lord Glenarvan. Laughton was originally announced as the character but Laughton's illness and subsequent death forced Disney to replace him with Hyde-White.
The Sherman Brothers - Robert B. Sherman and Richard M. Sherman - composed four songs for the movie. These included "Enjoy It", "Merci Beaucoup", "Grimpons" (aka "Let's Climb") and "Castaway" (as well as "The Castaway Theme").
According to show-business trade paper 'Variety', obstacles that the castaways had to survive included "giant condors, jaguars, flood, lightning, crocodiles, an avalanche, an earthquake, a huge waterspout, mutiny by Grant's former quartermaster, imprisonment by unfriendly Maoris and an erupting volcano".
This is the only filmed adaptation of the source French "Captain Grant's Children" ("Les Enfants du Capitaine Grant") novel by Jules Verne not have the book's or a similar worded title (e.g. The Children of Captain Grant (1996)).
By 1962, most theatrical films were shot for projection in either anamorphic or spherical widescreen. Despite the spectacle aspect of this production, aided by Peter Ellenshaw's special effects, the film was shot, surprisingly, in the standard academy (1.33:1) format.