This study examines whether parental investment and membership in social clubs are associated with safer sexual behaviors among South African youth. Participants comprised 4,800 randomly selected adolescents age 14 to 22 living in the Cape Town area in 2002. Logistic regression was used to examine associations between measures of parental investment and associational membership with reported condom use at first and most recent sexual intercourse, net of effects of HIV knowledge, age, education, population group, parental coresidence, and household income. Interaction terms were used to examine gender differences in associations between risk behavior and parental investment and between risk behavior and group membership. Participation in clubs and community groups is associated with safer behaviors. A mother's financial support (for clothing, school fees and uniforms, and pocket money) is negatively associated with condom use, particularly among young women, suggesting that material need impels vulnerability to higher risk behaviors. Social resources in households and communities mediate HIV risk behaviors among youth in Cape Town. (Contains 2 tables.)