Child sexual abuse occurs in all strata of society. The average age of the sexually molested child is 11 years. The victim knows the offender in 80 percent of the cases. Father-daughter incest is the type most commonly reported to authorities. The five family conditions that can lead to father-daughter incest include the daughter's emergence as the household's central female figure, the parents' sexual incompatibility, the father's unwillingness to seek an outside sexual partner, pervasive fears of abandonment and family disintegration, and unconscious sanction by the mother. Both professionals and caretakers need to be aware of the wide range of physical and behavioral signs of child sexual abuse, because it is not easily detected. Validating an allegation depends on investigative interviewing, the medical examination, and laboratory testing. Team management is needed in diagnosis and treatment. Prevention should be the responsibility of all professionals involved with children and should include training, a curriculum for students, materials directed toward potential abusers, monitoring of child care programs, parent workshops, and public awareness campaigns. List of indicators and 10 references