The authours have studied the disease caused by the Schistosoma Mansoni in Minas Gerais, Brasil. They have made an historical summary of their own work, begun in 1933 in Belo Horizonte. In 1937 one of the authors, seeing the gravity of the sanitary problem, brought it to the notice of the government of Minas Gerais. They publish the studies they made, including that of the artificial lake of Pampulha, Belo Horizonte and their plan for fighting the verminosis. They give the clinical aspects of the disease, calling attention to the most important, clinical and surgical, of the verminosis. They refer to the difficulties of the diagnosis, therapeutics and prophylaxis, showing the geographical distribution in Minas Gerais and publish a map, based on their own studies and those of other colleagues, made in 88 cities of Minas Gerais. The average that the authors found in the infested cities, was 13.70 % for the trematodo. They suggest, as they had already done in 1941, the creation of a National Service against Schistosomiasis in Brasil.