Community-based sex offender treatment programs have expanded in recent years in response to public concern about the significant increase in reported child sexual abuse allegations. The most popular treatment intervention for sex offenders involves cognitive-behavioral techniques that focus on modifying offense-related cognitive processes, taking responsibility for offending behavior, increasing social and interpersonal skills and emotional control, and reducing deviant sexual arousal. Data from an evaluation of a sex offender treatment strategy, implemented in England in 1991, indicate that sexual offending can persist for many years, sometimes with long periods between offenses. In general, research shows that sex offenders can be treated but that treatment programs vary in the extent to which they are successful with different client groups. Procedures for evaluating short-term and long-term changes in sex offenders after treatment are examined. The context in which treatment processes occur is considered with respect to treatment length, cognitive distortions, social functioning, sexual deviancy, relapse prevention, therapist effectiveness, and group work techniques. 17 references, 2 tables, and 1 figure