The purpose of this paper is to shed light on the concept of “university third mission”, whose growing importance has led institutions and researchers to look for indicators to assess this dimension. The need to evaluate these activities not only comes from the recognition that indicators could allow universities to understand their performance and foster accountability and improvement of management practices, providing effective value to society, but also from the greater emphasis put by governments on quality assurance in universities. However, while commonly accepted evaluation and ranking systems for the two traditional missions of the university now exist, the third mission lacks any cohesive methodology. Despite several initiatives in this direction, the collection of data and the development of indicators on third mission activities still keep many limitations. Starting from these considerations, we will try to answer the following research questions: Which are current indicators and methods to measure and evaluate the university third mission? What are the perspectives of development for the evaluation system of third mission activities at international level? We propose an approach based on the following steps. We will start from an analysis of the main international ranking systems, examining the extent to which they include an assessment of third mission activities; we will then investigate the main international research projects aimed at identifying comprehensive indicators for these activities; finally, we will conduct a case study analysis based on the Italian evaluation system, which recently included third mission as a dimension to be measured and evaluated in higher education institutions. This methodology puts in evidence the importance of finding adequate indicators to assess and evaluate the university third mission. The aim of our work is to map the main approaches to these topics at the international level, as well as to systematize the theoretical contributions, which are currently fragmented and lacking a systemic vision. The outcome of the application of appropriate indicators and methods to measure and evaluate the contribution of universities to social and economic value, is the improvement of quality assurance, which could allow universities to understand how they perform, to develop best practices and to provide efficient and effective value for society.