Precursors of adolescent sexual risk taking were examined in a multiethnic sample consisting of 443 children (51% girls) of National Longitudinal Survey of Youth participants. Respondents were 12-13 years old in 1994 and 16-17 in 1998. Controlling for demographic and contextual factors, self-regulation--but not risk proneness--was significantly (modestly) associated with overall sexual risk taking 4 years later. Analyses of individual sexual behaviors indicated that self-regulation may affect choices made after becoming sexually active (e.g., number of partners) rather than the initiation of sexual activity. Measures of parent and peer influence had independent effects on sexual risk taking but did not moderate the effects of self-regulation and risk proneness. Findings add to the growing literature on implications of self-regulation for individual development.