In the introduction, the author stresses the vastness of the sphere of action of activities comprised in providing sanitation systems and services, in a dual and contradictory society such as the Brazilian one. Next, he develops a brief survey of the history of sanitation in the country, after duly particularizing the interdependence between public health and the existence or the absence of sanitation. The organs encharged with the provision of the services are presented in chapter 3, and the sector's perspectives in chapter 4, being succintly analysed the factors which condition its crisis, as well as some alternatives for surpassing it. The conclusions are an effort to instill in the reader a deep hope of reaching the end of this century enjoying a real process of change, as concerns the quality of life of the Brazilian population.Importância do saneamento na solução dos problemas sociais brasileiros. Raio de ação das atividades envolvidas com provisão de serviços de saneamento. Instituições responsáveis pelos referidos serviços. Perspectivas do setor. Esperança de chegar ao fmal do século com processo real de mudança da qualidade de vida da população brasileira.