Demographically, incest offenders do not differ from the general population. However, unlike nonoffenders, when faced with life demands with which they cannot cope, they seek relief from the resulting stress through sexual activity with children. Sex offenders can be grouped into two basic types based on their primary sexual orientation and their level of sociosexual development. Fixated offenders are primarily sexually oriented toward children. Regressed offenders are primarily sexually oriented toward agemates but develop a sexual interest in children when confronted with conflictual adult relationships and increasing responsibilities and demands. The two characteristic patterns in incestuous families are a passive-dependent situation in which the husband relates to his wife more as a dependent child than as a competent partner and an aggressive-dominant situation in which the husband maintains a position of power. A wide spectrum of sexual encounters exist between adults and children. The offender's motivation and characteristics may activate or inhibit incestuous behavior. Clinical evaluation must focus on the risk of further offending, the need for and amenability to treatment, the treatment modality, and the treatment setting. Treatment issues include the offender's lack of motivation, the sexual offense as both a symptom and a crime, the offender's denial, the dynamics of secrecy, accountability, the offender's need for life skills, and the need to determine the issues prompting the offense. Careful assessment is also needed to determine whether outpatient treatment or residential treatment will be more appropriate. Case examples and four references are supplied.