PURPOSE: To better understand why adolescents initiate sexual activity at early ages, we conducted a systematic literature review guided by eight key elements outlined in an integrative theoretical framework. METHODS: Using the matrix method for literature reviews, we extracted-from 69 published studies-statistically significant and nonsignificant findings (related to the attempted prediction/explanation of adolescents' sexual behavior and intention) and organized them using the various integrative model elements. We also assessed these publications' methodological quality including each study's deployment of theory, appropriate design, and data analytic/reporting techniques. RESULTS: Three integrative theoretical framework elements-intention, perceived norms, and an environmental constraint variable, time home alone-emerged as stable predictors of sexual behavior outcomes in this body of literature. This analysis revealed, however, a literature that has remained rather stagnant regarding its methodological quality, over time. CONCLUSIONS: Implications for adolescent sexual health promotion practice and research are discussed.