The Erasmus student mobility programme allocates three explicit objectives to the experience of spending a few months studying in another European country: to benefit educationally, linguistically and culturally; to promote co-operation between institutions; and to contribute to the development of a pool of well-qualified, open-minded and internationally experienced future professionals (European Commission,1996). However, although not stated as one explicit objective, the programme has sometimes been referred to as one of the most powerful tools of European integration. However, little research has been done so far on how this may alter students' attitudes towards aspects of identity and feelings of citizenship. In this light, our study intends to cover this area of research by means of a set of quantitative and qualitative measures to determine the extent to which the Erasmus experience affected the sense of self as European citizens among a cohort of students from the University of Lleida (Catalonia, Spain), their position towards the notion of European citizenship and how this relates with the development of their plurilingual competence. Quantitative measures are based on the results of two questionnaires, one before and the other after the study abroad experience, whereas qualitative data were obtained through the analysis of discussion groups focusing on aspects of European vs. national identity and citizenship.