The relationship between being an adolescent child of a teen mother and sexuality-related outcomes was investigated using data from the National Longitudinal Survey of Youth. Adolescents whose mothers were teenagers at first birth were more likely to have had sex by age 16 than other adolescents. Gender moderated this effect, as this relationship was stronger for sons than for daughters. In addition, children of mothers with a lower level of education, adolescents who lived in poverty, and adolescents who resided with less than two biological parents at the start of the study were more likely to have had sex. (Contains 4 tables.)