The joint project between DG Joint Research Centre and DG Regional Policy on the construction of the EU Regional Competitiveness Index (RCI) aims at producing a composite indicator which measures the competitiveness of European regions at the NUTS 2 level for all EU Member States. The concept of competitiveness has been largely discussed over the last decades. A broad notion of competitiveness refers to the inclination and skills to compete, to win and retain position in the market, increasing market share and profitability, thus, being commercially successful. The concept of regional... competitiveness which has gained more and more attention in recent years, mostly due to the increased attention given to regions as key in the organization and governance of economic growth and the creation of wealth. An important example is the special issue of Regional Studies, published in 2004, fully devoted to the concept of competitiveness of regions. Regional competitiveness is not only an issue of academic interest but of increasing policy deliberation and action. This is reflected in the interest devoted in the recent years by the European Commission to define and evaluate competitiveness of European regions, an objective closely related to the realization of the Lisbon Strategy on Growth and Jobs. Why measuring regional competitiveness is so important? Because “if you can not measure it, you can not improve it” (Lord Kelvin). A quantitative score of competitiveness will help Member States in identifying possible regional weaknesses together with factors mainly driving these weaknesses. This in turn will assist regions in the catching up process. Given the multidimensional nature of the competitiveness concept, the structure of RCI is made of eleven pillars which describe the concept, taking into account its regional dimension, with particular focus on a region’s potential. The long-term perspective is, in fact, essential for European policy and people’s skills are understood to play a key role for EU future, as also underlined by the president of the Lisbon Council in his recent policy brief. For this reason the RCI includes aspects related to short and long-term capabilities of regions, with a special focus on innovation, higher education, lifelong learning and technological availability and use, both at the individual and at the enterprise level. A number of indicators have been selected to describe these dimensions with criteria based on coverage and comparability as well as within pillar statistical coherence. Most indicators come from Eurostat but where data was not available, alternative source were considered. A detailed univariate and multivariate statistical analyses have been carried out on the set of candidate indicators for the setting-up and refinement of the composite. Each choice with a certain degree of uncertainty has been submitted to a full robustness analysis to evaluate the level of variability of regions final score and ranking. The final RCI shows a heterogeneous situation across EU regions with Eastern and Southern European regions showing lower performance while more competitive regions are observed in Northern Europe and parts of Continental Europe.