Since the Italian unification, Southern Italy has lagged behind with respect the North and for this reason it has been subsidized for a long time, by the Italian government before and the EU later. The fact that despite a huge amount of subsidies the South has not been able to reduce the development gap with the North has urged scholars to focus their attention on the capability of the society to improve its own situation that means to take into consideration sociological aspects with respect to economic development. The concept of social capital that refers to the types of relations between individuals, could represent one explanatory factor of the Southern backward situation. The purpose of this study was to understand the relationships between social capital and socio- economic disparities among the Northern and Southern regions of Italy. According to the study, the Northern and the Southern regions of Italy present different degree of social capital. These seems that affect to somehow the diverse economic development of the North and the South.