This paper focuses on the introduction of a suitable method for the measurement of social capital in the context of rural development policies. We present an empirical application of the method to four case studies from the south of Italy. In order to overcome some limits affecting previous empirical research, we have grounded the measurement framework upon a clear decomposition of the concept of social capital characterizing three main dimensions: structural, relational and cognitive. This has allowed us to build five direct indicators for the core components of social capital created within the EU local agencies for rural development (the Local Action Groups). Moreover we have set a synthetic measure capturing the specific configuration of the internal social capital of the groups as a whole. (Contains 4 tables and 2 figures.)