Sex offender treatment as a specialized procedure is maturing, and more comprehensive approaches that treat co-morbid patient problems (e.g., mood and anxiety disorders, relationship conflicts, social skills deficits) have emerged. However, little attention has been given to the role of sexual dysfunction in the assessment and treatment of sex offenders. We propose that: (a) sexual dysfunction is a prevalent co-occurring sexual disorder in sex offenders; (b) sexual dysfunction is, by definition, a lack of sexual health, which diminishes overall life satisfaction; and (c) sexual dysfunction can be a contributing factor for some in maintaining offense-related arousal patterns and therefore is a potential contributor to sex-offense risk. This article describes the importance of treating sex dysfunction in selected cases when it is present among men in sex offender treatment, in order to improve the men's quality of life and to deter sex offense recidivism. A brief case example illustrates this benefit.