This paper proposes a new proxy of social capital based on the regional density of industrial districts. The advantage of this new proxy is to better deal, at least conceptually, with the main three problems related to the PI advanced by Paldam (2000) which are: the definition of voluntary associations, the intensity of the contacts and the so called “Benignness-weight problem”. In our analysis we show an empirical comparison between the behaviour of our index and that one of the Putnam Instrument across the Italian regions. To do so we use regional data in the 2001 from the Italian National Bureau of Statistics (ISTAT). One of the interesting results from the empirical application is that the new proxy and the Putnam’s instruments present similar patterns, even though with some exceptions.