In the regions we have worked in there had been found five patients of american visceral leishmaniasis before our researches, three in the State of Ceará and two in the State of Pernambuco. Eight other cases had been reported by viscerotomy in the State of Baía, district of jacobina. One case of Chagas' disease has been found in the State of Ceará. For the execution of our work we travelled through the States of Ceará, Pernambuco and Baía, in the very regions where the reported cases were found. At these places we made rapid epidemiological reports about those diseases. At the State of Ceará, zone of Cariri, we found two new cases of american visceral leismaniasis, the diagnosis of which was confirmed by the examination of the material of spleen punctures. Five cases of Chagas' disease shown by xenodiagnostic were found too. We collected flebotomus longipalpis Lutz & Neiva, F. villelai Mangabeira, F. limai fonseca and F. nordestinus Mangabeira and Panstrongylus megistus (Burm.) with 13.5% infected. We had negative results in the examination of domestic (dogs and cats) and wild animals. At the State of Pernambuco, district of Exú, we made inquiries about two cases of american visceral leishmaniasis previously refered and found no new cases. We collected, F. longipalpis Lutz & Neiva, Panstrongylus megistus (Burm.) and Triatoma brasiliensis Neiva; none was infected. Among the domestic animals (3 dogs) we found leishmaniae in liver and spleen of one of them. the results of the examination of 43 wild animals were negative. In the State of Baía, district of jacobina, we found along the cityline one case of american visceral leishmaniasis and in others regions of this district, three new cases, the diagnosis of which was confirmed by the examination of the pulp of the spleen; we also found two cases of Chagas' disease, by xenodiagnostic. We collected F. evandroi Costa Lima. F. lenti Mangabeira, and F. longipalpis Lutz & Neiva; Panstrongylus megistus (Burm.) (65.5% infected) and one single specimen Eutriatoma maculata (Erich.) Further we have found an infected specimen of p. megistus (Burm.) in tree burrows some distance from the houses. We examined four domestic animals (dogs and cats) and found one dog infected with S. cruzi.