Risky sexual behaviors have high personal, social, and financial costs. Family communication about sex can reduce risky sexual behaviors, but most research and teen health education programs focus exclusively on mothers and don?t address low rates of father-teen communication about sex. These gaps fail to address the potential of father-teen communication to protect teens from risky sexual behavior as well as barriers to this communication. Few studies assess whether and under what conditions father-teen sexuality communication effects teen sexual health or provide multi-reporter perspectives on father-teen sexuality communication. This mixed-methods study will assess father-teen sexuality communication and its associations with teen sexual behaviors, and investigate multiple family members? perspectives on father-teen sexuality communication. The proposed study applies an established conceptual model of mother-teen sexuality communication to fathers. The study will assess three aims: 1) Assess associations between father-teen sexuality communication and teens? sexual behaviors, 2) Investigate contexts of fathers? direct and indirect sexuality communication, and 3) Triangulate fathers?, second parents?, and teens? perceptions of father-teen sexuality communication. To address these aims, this study uses an explanatory sequential design in which quantitative findings inform qualitative interviews and analysis. Secondary survey data includes 952 urban high-school students (Aim 1). New interviews will be conducted with a purposive sample of 40 fathers and their families: 20 teens and 20 second parents are expected to participate (Aims 2 & 3). It is hypothesized that father-teen sexuality communication will predict teens? sexual behaviors, the strength of associations will vary by teens? gender, fathers? residential status, and familism, and teens? attitudes will explain associations between communication and behavior (Aim 1). Content analysis will be used to explore fathers? perspectives on father-teen sexuality communication and compare them across contexts and for fathers who do and do not talk with teens about sex (Aim 2). A modified constant comparative approach will be used to triangulate multiple family perspectives on father?teen communication (Aim 3). This work is significant in its assessment of whether and under what conditions father?teen sexuality communication predicts teens? sexual health and its in-depth, multi?reporter assessment of this communication. This study contributes to public health by guiding programs regarding 1) barriers to and supports for father-teen communication 2) how families perceive fathers? roles in sexuality communication, and 3) under what conditions father-teen communication supports teens? health. Its innovation lies in a triangulation approach which integrates multiple family perspectives on father-teen sexuality communication and its inclusion of fathers who do not talk with teens about sex. This study?s findings will contribute to research on how fathers can support teens? sexual health, multi-reporter perspectives on sexuality communication and the roles of gender and culture in this process.