This study evaluates the results of an educational campaign developed in an outlying neighborhood of São José do Rio Preto and the relationship between the population's knowledge and habits. Prior to and after the educational activities, samples were taken to measure level of knowledge concerning dengue and its vectors, breeding sites, and control measures. Potential breeding sites were also counted. Knowledge of the disease and its vectors and breeding sites increased, but the same was not true for control measures focusing on water recipients serving as potential breeding sites. There was no change in the number of breeding sites between the first and second stages of the research. Thus, despite increased knowledge, the local population's habits did not changes. These findings are worrisome, since the main goal of the educational campaign, i.e., the change of habits concerning breeding sites for dengue vectors, has not been achieved.