The control of the vector-borne transmission of Chagas disease in Brazil was organized as a national program in 1975, when two large entomological and sero-epidemiological surveys were conducted in the country in order to identify areas at highest risk of transmission and to guide inerventions regarding the chemical treatment of domestic vectors of the disease. The authors present the baseline data gathered through these studies and compare them with more recent data. The evaluation performed shows that the
transmission by Triatoma infestans is virtually interrupted and that the transmission by other native species of triatominae from different regions of the country is possibly very low. It is
emphasized the need to maintain permanent actions of entomological surveillance in order to prevent recurrent transmission.