In this family film, the Robinson clan — mother (Dorothy McGuire), father (John Mills) and their three sons, Fritz, Ernst and Francis — flee the reign of Napoleon to start afresh in New Guinea. When their ship gets damaged en route, the family takes refuge on a deserted island. The Robinsons learn to live in the wild, have various adventures and build an impressive house in a tree. However, while island life is full excitement, the question of whether to return to civilization looms.