Includes bibliographyImplementation problems have emerged as one of the key items in the international negotiating agenda. This paper analyses the experiences of Chile and Mexico in implementing trade agreements. The negotiations of FTAs have implied changing the institutional environment of Latin American countries. Transparency obligations are changing the way policies in general are formulated, adopted and implemented. Other obligations have created the need to introduce new legislation where it did not exist. Implementation takes place at different moments in time and at different stages of the negotiations and operation of the trade agreements. How implementation problems have been addressed and to what extent it has been effective is a major concern. In fact, these aspects are related to the activities developed by multilateral and regional organisations, both in support of multilateral and regional trade negotiations. But within the context of recent bilateral negotiations, specific chapters dealing with trade capacity building have been negotiated (CAFTA), current negotiations (CAN-US). The paper focuses it attention on the Chilean and Mexican experiences with trade agreements and provides explanations regarding their relative success.