This study assessed the influence of individual age and substance use, family support and communication, and partner support and communication on the frequency of unprotected sex among incarcerated adolescent females. Subjects (n = 273) completed a survey on psychosocial correlates and risk behaviors for sexually transmitted infections (STI). Communication with male partners and sex while under the influence have a significant impact on condom use. Findings highlight the necessity of providing assertive communication skills training and increasing self-efficacy as STI/HIV prevention components for adolescent females thus empowering their decision-making processes.