This research aims to carry out a comparative analysis of the trajectories of the basic sanitation public policy in two states: Mato Grosso and Mato Grosso do Sul. These two states, despite having started from common paths in relation to basic sanitation, since they were the same territory served by the same State Company, took different paths in the late 1990s, with Mato Grosso adopting a municipalized management model and Mato Grosso do Sul continuing with a centralized model in a State Company. From this scenario, this thesis is anchored in literature -such as on decentralization and local power, bureaucracy and state capacity, trajectory continuity (path dependence) and changes in public policies -to build the trajectories of policies and analyze the factors and internal and external dynamics that led to the two models. For this, the research makes use of a bibliographical review, exploratory analysis of quantitative data on the socioeconomic characteristics of the two states, differences and similarities of access to water and sewage services throughout the focus period (1960s to 2000s) and aspects operations of the State Companies Sanemat (MT) and Sanesul (MS). Still, the dissertation was also built from field research, with interviews with key people of basic sanitation in both states, allowing the construction of narratives and events that marked the change of model in MT and continuity in MS. As a result, this research identified factors internal to the Companies (such as organization, political-financial structure, relationship with municipalities, autonomy and bureaucratic activism) and external factors (window of opportunity and national context) that influenced the progress of each of the policies of basic sanitation.