The paper provides an analysis of the impact on trade of EU preferences in the agricultural sector. An explicit measure of the intensity of preference margins at the 6-digit tariff line level it is used. Moreover, the estimation framework takes into account the heterogeneity across exporters and products, as well as the potential selection bias implied by the presence of zero-trade flows. Preferences for agricultural products granted by the EU in 2004 are modeled by performing several regressions in order to compare the impact on different exporting countries and to highlight the contribution of different commodity groups. Even if the results confirm an overall positive impact of preferences on trade, significant differences emerge across products and between various exporters.