Sexual abuse can have negative consequences for children during the time of abuse as well as later in life. An important research question concerns the cycle of sexual abuse, specifically the likelihood that individuals who were victims of sexual abuse as children will become sexual abusers of children in adulthood. At the request of Congress, the U.S. General Accounting office completed a review and analysis of available published and unpublished research on the cycle of sexual abuse. Twenty-five studies were identified (the majority retrospective in design) that provided quantitative information relevant to the question, and their methodologies and results were summarized and analyzed. Although a number of retrospective studies found that a substantial percentage of adult sex offenders of children said they had been sexually abused as children, the majority of the studies found that most offenders said they had not been sexually abused during childhood. And although some studies indicated that sexual victimization in childhood may increase the risk that victims will become sexual offenders as adults, various design and measurement problems of both the retrospective and prospective studies precluded drawing definitive conclusions. Overall, the studies indicated that the experience of childhood sexual victimization is likely neither a necessary nor a sufficient cause of adult sexual offending. (Appendices outline the methods and results of retrospective studies of adult sex offenders of children and list the major contributors and research articles used in this report.) (KDFB)