Guided by the Information Motivation Behavioral Skills (IMB) model, we examine the alcohol severity/sexual risk relationship for juvenile offenders who are at extreme risk for HIV/AIDS due to situational vulnerabilities, substance abuse,1 and personality factors. Sexual risk behavior was analyzed by levels of alcohol use among 634 ethnically diverse adolescents in Miami between 1998 and 2002. Adolescents with the highest levels of alcohol use reported significantly higher levels of total and unprotected sexual activity and sex acts proximate to drinking. Alcohol use related problems require more attention by HIV interventionists. Alcohol severity may reduce the effectiveness of HIV interventions that do not address concurrent substance use.