The discussion of future research on the assessment and treatment of sex offenders addresses short-term objectives, long-term goals, and theoretical goals. Short-term objectives pertain to treatment process measures and pretreatment-posttreatment improvement. Long-term goals relate to the long-term effects of treatment. Theoretical goals involve explanations of the origin, maintenance, and modification of sexually deviant behaviors. In addition to discussing future research in the aforementioned areas, the article provides a historical perspective of the assessment and treatment of sex offenders and describes the types of evaluations and behavioral interventions currently used, together with some outcome data. A major requirement noted for future research is a fully developed theory which would suggest what categories of intervention should work. 66 references.