This paper attempts to define the "optimal" sex offender treatment program based on a review of the empirical literature and on the authors' clinical experience with sex offenders. An important first step in any treatment program is the proper assessment of the condition to be treated. Assessment of sex offenders should include the use of the penile plethysmograph and the polygraph, as well as the more traditional methods of psychosocial assessment. These physiological tools are also useful as adjunct treatment tools. It is asserted that restitution therapy be the operating philosophy of any good treatment program, and that various aspects of client-centered therapy, transactional analysis, rational emotive therapy, and reality therapy are particularly well-suited to the counseling of sex offenders. These modalities should be augmented with antiandrogen medication to dampen the offender's libido so that he may concentrate on the rational process of psychotherapy free of distracting sexual urges and images facilitated by androgen activity in the hypothalamus.