The objective of this study is to analyze the coordination between monetary and fiscal policy in Brazil, more precisely in the context of monetary and fiscal dominances through a theoretical and empirical analysis. The two policies are directly related, and a possible conflict between the two would be able to generate damage to the economic health of the country. An analysis of the theoretical literature that explains the main theories on the issue of dominances is made. The monetary dominance implies a surplus to keep constant the debt / GDP ratio. In fiscal dominance, the tax authority sets its performance regardless of its budget, announcing possible deficits and surpluses. There is currently no consensus on which of the two authorities is active and which is passive for the Brazilian case. In order to verify which of the two policies is dominant two methods were used, one based on the analysis by estimating models auto regressive of distributed lags (ARDL) and another involving the estimation of a structural auto regressive vector (SVAR) using monthly data for the period 2003-2013 priority for the Public Sector Net Debt (DLSP), public sector borrowing requirement (PSBR) and Selic rate. The causal analysis and response functions to impulses on the structural VAR, indicated that there is impairment of the tax authority to the level of public debt, leading to the conclusion that Brazil is in a monetary dominance regime.