In this paper, we examine the micro-level implications of social capital for the development of democratic citizenship. By using a recent East Asia Barometer survey in Korea, we determine whether social networks and social trust, two key components of social capital, cultivate virtues of democracy among ordinary citizens. First, the analysis shows that the Korean people as a whole tend to be involved in small informal groups. Most of them stay away from formal associations. Second, the Korean people tend to differentiate trust-in-principle from trust-in-action. It turns out that a majority of the people display competence-based trust, if neither generalized nor particularized trust. Third, associational membership has no role in promoting support for democratic institutions and principles; it merely leads to more political activism. Fourth, social trust plays a role in promoting support for democracy. Yet it has little to do with political activism. It is concluded that in Korea, social involvement contributes to democratic citizenship behaviorally, whereas social trust contributes to it attitudinally.