Childhood sexual abuse is one of the most significant social problems of our time and has long been associated with a wide variety of adverse psychological and health outcomes, including negative sexual health outcomes. Previous research has found a consistent association between childhood sexual abuse and higher rates of psychopathology, substance abuse, and HIV-related risk behaviors, particularly sex trading. However, the impact of childhood sexual abuse on psychological and health outcomes among men is less well-studied. Guided by a theoretical model that integrated elements of the stress process and the life course perspective, this study examined the impact of early sexual debut, early substance use initiation, adult substance use, and psychopathology on the relationships between childhood sexual abuse and two separate outcomes, sex trading and HIV risks, among a randomly-selected sample of 356 adult men in methadone maintenance treatment. Thirty-nine percent of participants (n=135) reported childhood sexual abuse. Participants with childhood sexual abuse were more likely to report earlier substance use initiation, higher rates of psychopathology, substance use in adulthood, sex trading and HIV risks. Findings from a series of mediational analyses suggest that the relationship between childhood sexual abuse and sex trading is partially mediated by substance use and psychopathology. On the other hand, the relationship between childhood sexual abuse and HIV risk was completely eliminated, when the substance use and psychopathology factors where included in the analytical model, representing a strong demonstration of mediation. These findings provide strong evidence for the roles played by early substance use initiation, adult substance use and psychopathology on the path from childhood sexual abuse to sex trading and other HIV risks. They highlight the need to design, test and implement HIV prevention programs for survivors of sexual abuse that intervene at different stages of the life course and that integrate substance abuse and trauma-related counseling with HIV risk-reduction behavioral skills.