The present longitudinal study of 330 adolescents used structural equation models to investigate whether (1) health-risk lifestyles exist among adults and adolescents, (2) parents' health-risk behaviors influence adolescents' health-risk behaviors, and (3) intergenerational transmission occurs by way of a health-risk lifestyle, by direct transmission of specific behaviors, or through both mechanisms. To address these questions, we estimated several models. The findings were generally supportive of the expectations. Results of single factor measurement models provided modest evidence for the existence of an underlying health-risk lifestyle factor among parents and adolescents. Results of structural equation models also demonstrated that parents' health-risk behaviors were transmitted to adolescents both at the lifestyle factor level and the unique component level. These associations prevailed even after controlling for family social status. However, parents' health-risk lifestyles mediated the effect of family social status on adolescents' lifestyles, net of the direct effect of family social status on adolescents' lifestyle. In these two-parent families, the effects of parents' health-risk lifestyles on adolescents seems to have gender symmetry. The findings of the separate models for boys and girls demonstrated that (1) fathers' health-risk lifestyle affected only boys' health-risk lifestyle, whereas (2) mother's health-risk lifestyle affected only girls' health-risk lifestyle. A similar gender moderating effect was not found for specific health-risk behaviors. Implications of these findings for future research and theoretical development are discussed.