We develop theory stating that international and market-specific social capital are two distinct forms of social capital which both increase international opportunity exploitation. We also argue that market-specific social capital mediates international social capital. Our theoretical developments are based on internationalization process theory and social network theory. Using data on 239 internationalizing SMEs, our results confirm that the effect of international social capital on opportunity exploitation is only mediated via market-specific social capital. Hence, we identify an internationalization process for social capital development in international business opportunity exploitation. Our contribution adds in several ways to existing international business research.