Because of the growing importance that the external dimension of the AFSJ is acquiring under the new institutional framework of the European Union, the activity the European institutions carry out in that domain is increasingly facing issues concerning the interaction with the international obligations assumed by the Member States. This article discusses this interaction in a two-fold manner. On the one hand, it examines the relationship between EU law and treaties concluded between Member States. On the other hand, it sets out the relationship between EU law and treaties concluded by Member States with third parties. On the basis of a broad review of both EU and Member States practice, the article observes the general (although not monolithic) Eurocentric attitude of the EU actors in approaching the matter and inquires into its implications under international law.