[Abuse in adolescence. Incest. Apropos of 21 cases]

While violent behavior and delinquency in youth have been extensively described, the different patterns of violence that adolescents are subjected to in their families are far less known. Physical abuse is probably as frequent as in childhood and offers some distinctive features because of its appearance or prolongation in adolescence. Moreover, sexual assaults become more important, especially in girls. From review of the literature and the experience of 21 cases of incest observed in the Adolescent Medicine Unit of Hospital Bicêtre, we discuss the circumstances, impact on adolescents and role of the professionals involved. The majority of these cases of incest occur in an impoverished atmosphere, both on psychological and social levels. Intervention strategy is often very delicate.