This paper analyses how identity and citizenship are reshaped in cross-border areas after the implementation of European Union (EU) cross-border-cooperation programmes and civil society mobilization. The 1990s witnessed extensive debate about the emergence of a new kind of citizenship in Europe where =civil society participation‘ influences EU policies and politics and result in novel (national ethnic) identities. In this context, the paper explores the impacts of EU cross-border-cooperation and civil society mobilization policies in the Upper Adriatic area. It demonstrates the significance of ethnic minority groups in cross-border civil societies and their role in fostering relations, mutual understanding and integration across different borders. At the same time, it analyses the capacity of nationalism to re-activate a process of border creation, ethnic mobilization and produce irredentism. First, the paper offers a brief theoretical background on citizenship and its main components (rights, identity and participation) and defines what =participation‘ means in practice. Second, it investigates how different cross-border, grass-root stakeholders relate to each other. It explores how the implementation of cross-border-cooperation projects and interaction between these individuals construct new meanings, interests, and values, leading to revisit their identities. Third, the paper analyses the new EU regulation 1082/2006, generally known as the European Grouping of Territorial Cooperation (EGTC), and questions whether this can be the channel through which sub-national actors from different sides of a border overcome =border antagonistic‘ relationships and build a =transnational‘ border region. Ultimately, the paper argues that the constant interaction between societal and political cross-border actors at the local/elite level is leading to greater mutual understanding, long-term transnational initiatives and an increasing emphasis on shared interests and values.