This study explores the impact of social capital on innovation by constructing a more general measure of social capital, which consists of generalized and institutional trust, associational activities and civic norms. We test the hypothesis that social capital has a positive impact on innovation at the national level. After controlling for research and development expenditure and human capital, we find that there is a positive relationship between social capital and innovation. Social capital interacts with entrepreneurship; the strongest relationship is between associated activities and entrepreneurship. This study supports the need to build strong social relationships in today's networked economy.