Childhood sexual abuse (CSA) has been associated with HIV/AIDS risk behavior; however, much of this work is retrospective and focuses on women. The current study used semi-parametric mixture modeling with youth (n = 844; 48.8% boys) from the Longitudinal Studies of Child Abuse and Neglect (LONGSCAN) to examine the link between trajectories of CSA (2 to 12 years old) and HIV/AIDS risk behavior at age 14 (i.e., sexual intercourse & alcohol use). Trajectory analyses revealed a link between a history of CSA and the development of risky behavior. In addition, trajectories for physical and emotional abuse, but not neglect or witnessed violence, contributed to risky behavior over and above the role of CSA. Child gender did not moderate the findings. Findings highlight the significance of CSA histories, as well as the broader context of maltreatment, for better understanding the development of risk behaviors in both girls "and" boys. (Contains 5 figures, 2 tables and 2 footnotes.)