The present study investigated how volunteering was influenced by individual resources and social capital among four racial/ethnic groups of adults aged 50 and older. The data came from the California Health Interview Survey, a statewide sample that includes non-Hispanic Whites ( n = 18,927), non-Hispanic Asians ( n = 2,428), non-Hispanic Blacks ( n = 1,265), and Hispanics ( n = 3,799). Logistic regression models of volunteering were estimated to explore the effects of human and social capital within and across the racial/ethnic groups. Compared to Whites, racial/ethnic minority adults volunteered less. Although education was a significant predictor of volunteering across all groups, the findings indicated group-specific factors related to human and social capital. Results showed similarities and differences associated with volunteer participation among diverse racial/ethnic groups. The findings underscore the importance of understanding ways of creating inclusive opportunities for civic engagement among an increasingly diverse population.