The authors summarize the research about each age group separately, with a view toward contrasting the population and identifying critical features that are relevant to treatment and public policy. Characteristics, assessment, treatment, and public policy issues are discussed for each developmental group. Regarding children who sexually abuse other children, the focus is on behaviors that go beyond the normal curiosity that children have regarding one another's bodies. This is problematic sexual behavior that can cause problems for the child and others if not treated properly. The discussion provides guidelines for assessment and treatment. Concerning public policy toward such children, there is little evidence to suggest serious long-term risk to the community from most children with problematic sexual behaviors; a range of short-term outpatient interventions yield good results in most cases. Juvenile sex offenders who victimize children are a heterogeneous population. Clinical assessments of these juveniles are done to determine strengths and weaknesses, to identify amenability and appropriateness for treatment, and to determine the youth's psychological status and social ecology. A wide variety of clinical treatment approaches for juvenile sex offenders have been described in the literature, including behavioral conditioning, pharmacological approaches, family systems approaches, rational-emotive therapy, music and art therapy, cognitive-behavioral approaches, relapse prevention, and ecological multisystemic approaches. Although juvenile sex offenders should be processed through the juvenile justice system, some policies applied to adult sex offenders, such as registry and notification requirements, may not be appropriate for juvenile offenders. Regarding adult sex offenders, the most common psychological profile of a child molester is that of a psychiatrically nondisturbed individual; however, some comorbid psychiatric or behavioral conditions are relevant to treatment planning and risk assessment. Concerning treatment, most programs operate from a cognitive-behavioral perspective and include relapse prevention. Public policy regarding adults who sexually victimize children is heavily rooted in a criminal justice tradition. Generally, efforts at assessing, intervening, preventing, and developing sensible public policies pertinent to those who sexually abuse children have yet to address the heterogeneity of developmental groups that perpetrate such abuse. 183 references