This paper addresses the impact of violent conflict on social capital, as measured by citizen participation in community groups defined for four activity types: governance, social service, infrastructure development and risk-sharing. Combining household panel data from Indonesia with conflict event information, the authors find an overall decrease in citizen contributions in districts affected by group violence in the early post-Suharto transition period. However, participation in communities with a high degree of ethnic polarization is less strongly affected and even stimulated for local governance and risk-sharing activities. Moreover, individual engagement appears to be dependent on the involvement of other members from the own ethnic group, which points to emphases on bonding social networks in the presence of violence. Finally, in conflict regions, the wealthier households are more likely to engage into cooperative and infrastructure improvement activities, while they are dropping from security groups. On the contrary, the poorest households get more involved in social service activities and less in infrastructure groups. The results illustrate the danger of generalizations when dealing with violence impact on community activities.