The chapter first reviews the literature on ethnoregionalist parties. Since the 1970s, several waves of political mobilization have demonstrated the relevance of this party family for territorial politics. The discussion covers the conceptualization and labelling of the ethnoregionalist parties as well as the current state of the art. The analysis of the performance of ethnoregionalist parties looks at the electoral, office and policy success of the party family and their determinants at the regional, national and European level. The chapter also looks at the Euro party organization of ethnoregionalist parties and provides evidence on the position of the party family regarding European integration and its change and continuity over time. The chapter concludes with an assessment of whether there has been a fundamental transformation or a consolidation of political dynamics within the party family over the last decade.