Regional and Cohesion Policy constitutes one of the major priorities of the European Union. As a result of the increasing concern of public authorities and society towards the use and results of public resources, evaluation activities have become an integral component of the process of modernization and rationalization of public policies, which has led to the institutionalization of evaluation in the European Regional and Cohesion policy-making process. In this context, this paper presents, first, a theoretical and conceptual revision of both regional policy and its evaluation. The historical evolution explains the plurality and methodological diversity that exists nowadays in the theoretical field of the evaluation of regional policy. Secondly, the results of a detailed analysis of the evaluation methodologies that are actually applied by regional development plans and programs in the European Union are exposed, to finally show the existing discrepancy between theory and practice in the field of evaluation of European Regional Policy.