This contribution is based on a SPRINT-EIMS project involving a ''horizontal'' inventory and critical analysis of existing studies on the measurement and evaluation of regional technological innovative potential.(1) After the presentation of a conceptual scheme aiming at reflecting on the functioning of a ''Regional System of Innovation'', the main trends in methodological approaches to the evaluation of regional innovative potential in the European Union are discussed, pointing to the necessity of moving progressively towards a methodology taking into account interactions, both locally and externally, between the various components and actors of the innovation process. There is no single best-practice methodology in this respect: the use of an ''eclectic'' assortment of methodological approaches is investigated and the recommendation given to develop data bases on innovation at regional level.