By definition, democracies depend on citizens' involvement in their governance. Laws and institutions are necessary but insufficient for sustaining such systems; democracies also depend on certain psychological dispositions in the people, with an ethic of civic participation, trust in others, and tolerance of dissenting views topping the list. The late adolescent/young adult years are a formative period for developing such dispositions, but experiences are critical. In the past few decades, colleges and universities have made engagement in community service and public affairs a more common part of the undergraduate student's experience. In this article, the authors explore whether students' psychosocial well-being is likely to benefit from such engagement. They first discuss the relationships between civic engagement and psychosocial well-being. Then, they describe the mechanisms whereby engagement in civic action leads to psychosocial well-being.