Abstract We use novel survey data from Italy to shed light on key questions regarding the measurement of social capital and the use of social capital indicators for empirical work. Our data cover a sample of over 600,000 respondents interviewed between 2000 and 2015. We identify four distinct components of social capital—(i) social participation, (ii) political participation, (iii) general trust and (iv) trust in institutions—and examine how they relate to each other. We then study how each dimension of social capital relates to various socio-economic factors, both at the individual and aggregate levels, and to various proxies of social capital commonly used in the literature. Finally, building on previous work, we investigate to what extent different dimensions of social capital predict differences in key economic, political and health outcomes. Our findings support the view that social capital is a multi-faceted object with multiple dimensions that, while related, are distinct from each other. Future work should take such multi-dimensionality into account and carefully consider what measure of social capital to use.