This is the result of on epidemiological study of 2.416 cases of Schistosomiasis observed in the city of Rio de Janeiro, in Guanabara State, from 1960 to 1968. The patients were migrants from 275 districts (municípios) of 18 States in Brasil and were supposed to be "indicators" of the disease in the places where they came from (provide they had no multiple trips or migrations that difficult the assessement). It was observed that the states of Pernambuco, Paraíba, Minas Gerais, Bahia, Sergipe and Alagoas contribute with 80% of Schistosomiasis migrant cases to the Guanabara state. Most of them were in the third and fourth decade of life. There was a light prevalence of females and an important predominance of mulattoes and whites.