Article dans une revue: This paper investigates how tariff liberalization has aected exporting at the product-destination level in emerging countries. We use a highly disaggregated (6 digit level of the harmonized system HS classication) bilateral measure of market access to compare taris applied in 1996 and 2006, which includes the timing of the Uruguay Round and episodes of bilateral liberalization. Our econometric estimations consider impacts of tari cuts on three components of the trade margins: extensive margin of entry (new trade relationships at the product-destination level), extensive margin of exit (disappearance of existing relationships) and intensive margin of trade (deepening existing relationships). Our main estimates indicate that a reduction of bilateral applied taris of 1 percentage point increases the extensive margin of entry by 0.1% and the intensive one by 2.09%, while it reduces the extensive margin of exit by 0.25%.