Drastic modifications in agrarian space, with the reductions of primary forests, along with changes in rural production systems have led to the growth of salaried employment and also caused rural workers to move to the peripheral areas of cities. There has also been an intense and continuous intervention undertaken by the Superintendência de Controle de Endemias (SUCEN) through the use of pesticides in the fight against triatomine bugs in houses and peridomestic areas of the State of S. Paulo. All these factors have contributed to the interruptions of the natural transmission of Chagas' disease in S. Paulo. The next step in the program was the integration of vertical vector control into primary health care involving community participation. The several years of SUCEN's work among the rural communities has encouraged them to notify the presence of triatominae bugs, and prompt response to each notification has led to the growth of the process of permanent participation. Data from 1985 and 1986 showed that 85.6% of the bugs captured inside houses were notified by the population, which confirms that the best way to maintain the epidemiologic surveillance of Chagas' disease by the mobilization of local communities for effective participation in vector surveillance.