Using two waves of panel data from Americans' Changing Lives (House 1995) (N = 2,681), we examine the relationships between volunteer work in the community and six aspects of personal well-being: happiness, life satisfaction, self-esteem, sense of control over life, physical health, and depression. Prior research has more often examined the effects of voluntary memberships than of volunteer work, has used cross-sectional rather than longitudinal data, and, when longitudinal, has emphasized social causation over selection effects. Focusing only on the consequences of volunteer work overlooks the antecedents of human agency. People with greater personality resources and better physical and mental health should be more likely to seek (or to be sought for) community service. Hence, we examine both selection and social causation effects. Results show that volunteer work indeed enhances all six aspects of well-being and, conversely, people who have greater well-being invest more hours in volunteer service. Given this, further understanding of self- versus social-selection processes seems an important next step. Do positive, healthy people actively seek out volunteer opportunities, or do organizations actively recruit individuals of these types (or both)? Explaining how positive consequences flow from volunteer service may offer a useful counterpoint to stress theory, which has focused primarily on negative life experiences and their sequelae.