This article presents the central aspects of the structure, functioning and dynamics of municipalities in Brazil, especially since the last 35 years, which coincide with the new constitutional framework that guarantees them autonomy as a federal entity. In this process, the localities underwent significant changes in their administrative, political, financial and legal roles. The process of decentralization of policies combined with the mechanisms of participatory democracy and lack of state capacities continue to generate very important challenges for assigned roles in terms of the provision of public policies and action in favor of the local interest.