Since the middle of the 90’s, rice has been one of the main agricultural products imported by Brazil, particularly from Uruguay and Argentina, which very often raises concerns to Brazilian rice producers. This paper aims to analyze the factors that determine the Brazilian rice imports, and therefore proposes an economic model to examine these trade flows in Mercosur, assuming that the Brazilian rice imports results from a domestic demand surplus. An econometric model Vector Auto-regressive (structural VAR) is applied. Results show a strong relationship among rice imports and domestic rice prices, as well as the exchange rate. A significant effect of import prices over domestic prices has been verified. The quantity of rice imports relates positively to an increase of domestic prices and negatively to an increase of import prices, as well as increases in the exchange rate. A bicausality relationship is verified between domestic and import prices for rice. One of the major conclusions is that Brazilian rice imports answer immediately to changes in domestic prices and exchange rate and react one quarter later to changes in import prices suggesting a delay over rice importers to substitute imports by the domestic rice.