A very important part of world production is nowadays organized along Global Value Chains (GVCs). The success of individual countries in the global economy depends on their ability to combine domestic and foreign value added in order to produce exports, which are later embodied in other products or consumed as final goods and services. The pervasiveness of GVCs strongly affects the interpretation of classical international trade measures computed in gross terms, emerging the need to assess trade flows in value added terms. This article analyzes the participation of the Portuguese economy in GVCs in the period 1995-2011. On the one hand, the level of foreign value added in exports indicates the degree of integration in GVCs. On the other hand, the re-export of national value added incorporated in imports provides indications on the positioning in the value chain.