the objective of this paper is to analyze the relationship between the mexican executive and legislative branches in foreign policy issues during the 20002006 period. while in quantitative terms there was not a significant change, the relationship between both branches was characterized by being conflictive. the key argument is that the confrontation between the executive and the legislative in foreign policy issues was due to the electoral interests of the key political actors. the paper is divided into three parts. the first one describes the theoretical and legal framework that explains the relationship between the congress and the executive in foreign policy matters. the second part analyzes this interaction from a quantitative perspective. finally, the last part evaluates the relationship from a qualitative criterion, using the cases of the mexican relationship towards the united states, cuba and venezuela.