Purpose: The purpose of this study was to investigate the role of age, gender, peer, family, and culture in adolescent risky sexual behavior for Cambodian and Laotian (Lao)/Mien youth. Methods: We obtained cross-sectional, in-home interview data including measures of individualism, collectivism, acculturation, risky sexual behavior, peer delinquency, parent engagement, and parent discipline from a sample of mostly second-generation Cambodian (n = 112) and Lao/Mien (n = 67) adolescents. Data were analyzed using step-wise, hierarchical multiple regressions. Results: Peer delinquency and age (older) were significant predictors of risky sexual behavior in both groups. Parent discipline also significantly predicted risky sexual behavior, but only for Lao/Mien adolescents. Vertical and horizontal individualism were associated positively with risky sexual behavior for Cambodian youth whereas collectivism (horizontal) was associated negatively with risky sexual behavior for Lao/Mien youth. Acculturation was nonsignificant in both groups. Conclusions: In addition to age, parents, and peer groups, the findings suggest that culture also matters in risky sexual behavior, particularly for Cambodian and Laotian youth. (c) 2006 Society for Adolescent Medicine. All rights reserved.