Abstract: Sanitation is a service that needs to be provided in order to promote good health and the well-being of people. Thirteen years after the establishment of the Sanitation Law in Brazil, the sector still experiences several challenges in providing adequate access to sanitation services for the population. According to national standards, only about 55% of the population has access adequate sanitation services. There is a growing need to understand the linkages between the legal framework and the development of the institutional structure, and how the current model of the sanitation sector could be improved. This study describes the legal framework of the Brazilian sanitation sector and discusses the role of the public sector with focus on the potential impacts of increasing the participation of the private sector.