Trade liberalization can generate substantial distributional conflicts. This paper measures the impact of increasing trade openness between Mexico and the U.S. resulting from NAFTA on the income of small versus large cash-crop farmers in Mexico. Benefits resulting from higher prices of export goods as well as losses incurred from greater import competition are considered. First, relating NAFTA cuts in trade restrictions to border prices of Mexican exports and imports, I find that NAFTA-induced tariff reductions decreased the border price of corn, Mexico’s main agricultural import, and increased the border prices of tomatoes and melons, Mexico’s main agricultural exports. Then, I find that, among cash-crop farmers, the rise in fruit and vegetable prices benefited small farmers more than large farmers; while the drop in corn prices hurt large farmers more than small. Finally, the analysis at the regional level shows stronger results in the central region where trade liberalization increased the level of earning of poor farmers relative to those of large farmers. These results are consistent with observed cropping patterns and regional characteristics.