In the context of Brazil's federal system, it is pertinent to deepen the competences of metropolitan municipal public administrations and federal states with regard to the management of public functions of common interest. The regulatory framework for these public functions is analysed, as well as the need for healthy changes for municipal public administrations and federal states. Healthy changes are suggested for municipal and state public administrations, not only in terms of thematic and structuring legislation, but above all in terms of changing attitudes when tackling the metropolitan issue.