Podoconiosis or endemic non-filarial elephantiasis is produced by deposits of inorganic materials in the lymph node of the lower extremities. The presence of elephantiasis in São Tomé Island and its prevalence in two districts are documented. Epidemiological aspects of the disease as well as clinical and pathological data of some of the cases are illustrated. With all these data and the physical characteristics of the island we suggest that elephantiasis in São Tomé is of geological obstructive origin: podoconiosis. The importance of non-medical measures to eradicate this disease are underlined.