Special research on the breeding biology of Crocodylus cataphractus has been done in the Tai National Park, one of the last primary rain forest of West Africa. The seasons for nest construction, incubation period and hatching time were determined. Kind, size and dispersion of nests are described. Information on egg size, clutch size, nest temperature and humidity during incubation is given. Some additional data has been obtained from a breeding-stock of Crocodylus cataphractus in the Abidjan National Zoo.