Although clinical psychological assessment is generally expected to be specific to particular interventions with demonstrated efficacy, there is insufficient empirical evidence on which to prescribe clinical assessment practice with sex offenders. The best strategy is to examine interventions that target personal and circumstantial characteristics empirically related to commission of sex offenses or to recidivism among sex offenders. The most reliable and robust empirical differences between sex offenders and other people pertain to sexual preferences. The best available assessments of the risk of recidivism are provided by actuarial systems that include indicators of deviant sexual preferences and of persistent antisociality across the life course. The Hare Psychopathy Checklist is the best available measure of such antisociality. Equivocal evidence supports the use of some assessments of specific attitudes and symptoms. This entry discusses the psychological assessment of men who have sexually assaulted women and children; much of the discussion also applies to assessment of adolescent male sex offenders.