This dissertation aims to assess the effect of institutional variations in Executive-Legislative relations over policies in Brazilian states. It analyses Legislative institutions, governor’s agenda and leadership, and government coalitions. The first part of the text is based on scholarship on American state legislatures and the Brazilian Congress, to estimate the best approaches to assess the institutional diversity on the ability to legislate and to oversight the Executive on Brazilian state legislatures. Subsequently, it is performed case studies concerning the state legislatures from Minas Gerais, Rio de Janeiro, Rio Grande do Sul and São Paulo and their participation on State reform policies, the main issue on gubernatorial agenda for the studied interval. Finally, it concludes that, institutions, although important, are incomplete to explain how the political process for policy-making occur in Brazilian states.