This paper is the summary of the IAREG (Intangible Assets and Regional Economic Growth) European project, which analyzed the role of intangible assets (IA) on regional economic growth. We focused on some of the most relevant intangible assets, for which statistical information is available and where the consortium had more expertise. Consequently, in this paper we put special attention in four big factors: knowledge capital, human capital, social capital and entrepreneurship capital. Additional to the main characteristics of each of these IA (related with their measurement and their effects on regional economic growth), we also analyzed the ensemble effects of these IA over the location of firms. For each asset, we describe its main characteristics, the indicators for its measuring and its limitations, as well as the main results associated to its impact on regional growth. We must outline that in order to improve the analysis of the effects of the IA in regional economic growth it is necessary to develop more and better databases. We present some thoughts in this respect, based on our research experience. Finally, we give some policy implications and recommendations.