abstract  This study investigates the mediating role of information sharing in the relationships between dimensions of social capital and firm competitiveness, thereby positing a possible explanation for the divergent empirical results of the social capital–performance relationship in the existing literature. The study uses a sample of 108 Hong Kong-based Chinese family-owned firms from the manufacturing sector. Largely supporting the theoretical predictions, the results from multiple regression and structural equation model tests show that information sharing plays a mediating role in the relationships between three dimensions of social capital (trust, network ties, and repeated transactions) and firm competitiveness improvement.