Sexual offense, also called sexual abuse, committed by adolescents is a complex and heterogeneous phenomenon that affects people of different beliefs, ethnicities, educational backgrounds and socioeconomic status. It is a topic little explored in Brazil and which lacks statistical data, unlike what happens in the international scenario. This study was designed to examine the characteristics, environments and relationships of adolescents in intrafamily sexually abusive situations. It also aims at identifying the risk factors and the future prospects of these youths to prevent recidivism. This is a qualitative study, built on the systemic perspective, whose assumptions are complexity, intersubjectivity and contextualization. The research was conducted with four teenagers between 12 and 18 years of age, as well as with their mothers and/or guardians. The setting was a child and adolescent mental healthcare unit, which comprise the Children and Adolescent Protection Network of Brazil's Federal District. Data collection took place on the premises of this unit which provides Multi-family group therapy (MFGT), both for the victims and sexual offenders. Three instruments were used in the study: 1) a semi-structured interview that had been built and used by the professional staff of that unit; 2) the "ERASOR" -Estimative of Risk Adolescent Sexual Offense Recidivism checklist (Portuguese version); and 3) a graphic resource to elicit the teenagers' future prospects. The interview focused on the history of the family, circumstances in which the events occurred, consequences for the family group, measures adopted by the people responsible for the adolescents, and the institutions they resorted to after the abusive events. The ERASOR checklist was completed by the professionals focusing on different risk factors for reoffense, such as the history of sexual offenses committed by adolescents, as well as their psychosocial and family/environmental functioning. The graphic resource was meant to explore the teenagers' views through the drawing of their future perspectives. Data analysis revealed that violence, inside and outside the family, favored sexual offense situations, in which responsibility for the act was attributed to the victim and minimized by the perpetrator of the offense. As far as the reoffense potential is concerned, the analysis suggests that the offenders themselves had suffered sexual abuse. Such is the case of two subjects. Prior sexual abuse suffered by these offenders has not been completely unraveled, neither treated. In line with these results, young people's drawings expressed fear and ambivalence about the process of overcoming the prevailing offensive episodes and their history, especially because they belong to families with little protective availability. On the other hand, potential positive and optimistic outcomes were detected. Juvenile sexual offense is a problem that concerns all members of the family and requires to be dealt with in an integrated and comprehensive manner. These individuals need e...