Science and Technology Parks (STPs) have made a positive contribution to regional development in the last decades. In general, the assessment of their level of performance has been based on two major variables: number of new companies and number of new jobs created. In this paper we propose the use of social accounting to measure the social value (SV) generated by STPs as an additional tool to assess the level of contribution of STPs to social development. Social accounting could be of interest for policy makers and regional governments in order to evaluate regional STPs and their social performance. In addition, in this paper we present an innovative methodology for calculating SV. Instead of using primary data to calculate SV (through interviews or consultations with individual stakeholders), we propose the use of secondary data available in open databases to measure SV. In this way, the measurement of SV for a large number of individual organizations can be achieved using a limited amount of resources. In this line, and as a seminal implementation of this methodology, we calculate the SV generated by four STPs in two different regions and countries belonging to the European Union using secondary data. Thus, the main contribution of the paper is twofold: on one hand it proposes social accounting to assess the performance of STPs through the calculation of SV, and on the other hand it implements a new methodology to calculate SV which requires the use of a lesser number of resources.