Background Incest is defined as any sexual activity between close blood relatives including step relatives and family members who are forbidden by law to marry. It is a problem that can be seen in all the social classes in developed and undeveloped societies.

Six families are described in which 10 sons were involved incestuously with a natural father (N=4) or step-father (N=2). Father-son incest as a part of the spectrum of child abuse appears to be a more frequent clinical entity than was thought previously.

Retrospective data were entered anonymously by 1,521 adult women using computer-assisted self-interview. Nineteen were classified as victims of father-daughter incest, and 241 were classified as victims of sexual abuse by an adult other than their father

A case of father-son incest is presented. There were three sexual involvements over a period of 6 weeks that ranged in activity from genital fondling to anal penetration. The father was the initiator of the activity and was drunk during each of the episodes.