The aim of this review is to assess the costs of 'brain drain' in EU Member States in terms of loss of initial investment in tertiary graduates, with a reference to the intra-EU migration of highly skilled workers. The analysis proceeds as follows. First, a brief discussion of the methodology used is presented. Second, an overview of studies related to the different categories of skilled workers is provided. Third, estimates of the detrimental and beneficial effects are discussed. Finally, an overall appraisal and concluding remarks are provided.