The authors present at the beginning, the evolution of the attack against T. infestans, main vector of Chagas' Disease in the State of São Paulo (Brazil). They stress that at first there was a decline in the density of these insects in the counties worked periodically. This decline in density was followed by the reduction of the infection rate, by T. cruzi and Machado Guerreiro positive reactions. When the conditions became suitable, Pedreira de Freitas' Selective method was introduced, making possible the improvement of the spraying technique and capture as well as the amplification of the protected area. They consider that a control campaing of the domiciliary vectors of Chagas' Disease present different phases and they try to explain when and how, in some counties in the State of São Paulo they reached the Surveillance phase as preconized by Emmanuel Dias. A pilot area was established, where methods of work are being studied and people hired in the Surveillance areas are being trained. Finally, they show that T. sordida and P. megistus are not reacting satisfactorily to the present method of attack.
