Section I summarizes sex offending laws and policies since 1985, outlining the criminal codes for all sex offenses, with attention to sex offenses that involve physical contact with the victim. Section II discusses the prevalence of sex offending in the Netherlands, presenting data on recorded crime, victimization, prosecution, sentencing, and treatment. Subsections address juvenile and female sex offenders. The prevalence of sex offenses in the Netherlands is comparable to that of other European countries. Prosecution and sentencing patterns for sex offenses have been fairly stable in recent years. The likelihood that a prosecuted case will result in a sanction has increased considerably for cases that involve sexual assault or offenses against minors. Treatment modalities for sex offenders vary. Almost half of convicted offenders enroll in treatment. Section III details research findings on sex offenders and sex offending over the past 25 years. Victim studies are first reviewed, distinguishing findings, whenever possible, by age and gender of the victims. This is followed by studies of sex offenders and the etiology of sex offending. Categories of sex offenders such as pedophiles and juvenile sex offenders receive the most coverage since they have been studied extensively. Criminal careers of sex offenders are discussed as well. Section IV contains policy recommendations and a research agenda. There have been few comprehensive studies on the etiology of sex offending or on risk factors. There have been no studies on treatment effectiveness, although there is a clear association between the risk of reoffending and the failure of treatment. 4 tables, 6 figures, 69 references, and appended provisions for sex offenses in the Dutch Criminal Code