The expansion of the European Union during the 1980s with the Mediterranean region countries was a major challenge both for the new Member States and for the Community as a whole. The new Member States, i.e. Greece, Spain and Portugal, were poorly developed in economic terms, with a high proportion of the agricultural sector in overall production and employment structure. Still, the concerns about the future turned out to be unfounded, and the impulse of the accession process and the necessity to compete on the common market brought certain advantages both to existing and to new Member States, thus enforcing certain changes in the structure of production and employment in the economies discussed in this paper. Today, the Mediterranean region states, irrespective of the success achieved in the past years, are again facing the need to resolve certain important economic problems related to the global fi nancial crisis. This paper discusses one of the aspects that strongly contributes to the present diffi cult socioeconomic situation of the contemplated region, i.e. evolution of the sectoral structure of employment and GDP during the European Union membership, with special consideration of the situation in agriculture.