The study evaluates the impact of some tax policies upon the rice sector in the Rio Grande do Sul (RS) state, in the Mercosur context. The impacts of the following decisions, regarding tax policy, are examined: (a) elimination of the fiscal benefits adopted by Brazilian states; (b) concession, by the government of RS, of a fiscal credit to the rice production in the state; (c) equalization of the tax rate related to the value added tax (ICMS) among all the Brazilian states at the rates of 7%, 4% and 0%. The study refers to the year of 2006 and projects some results for 2020. One of the conclusions of the study is that following the present fiscal policy legislation and equating, in all states of Brazil, the tax rate of ICMS at 7% would result in the highest benefits to the rice producers of RS state. On the other hand, given the actual market situation, setting the ICMS tax rate equal to zero, in all the Brazilian states, would result in the lowest price for the rice consumer in Brazil.