Numerous Western empirical studies exist regarding the influence of boards of directors on corporate social performance (CSP). However, research on the effects of board characteristics on CSP in Korean firms remains insufficient in both theoretical depth and the quantity of empirical studies. This paper derives hypotheses about the effects of corporate boards on CSP using agency theory and resource dependence theory, and empirically tests these hypotheses using domestic Korean firms. In the context of agency theory, the relationships between the equity ownership of inside directors and outside directors and CSP were examined. In the context of resource dependence theory, the relationships between board size and the education level of board members and CSP were analyzed. Empirical analysis of domestic listed firms from 2003 to 2007 revealed a significant negative relationship between inside directors' equity ownership and CSP from the perspective of agency theory. From the resource dependence theory perspective, board size and the education level of board members were each found to have a significant positive relationship with CSP. Based on these results, this study discussed the implications of the findings.