Background: Teen-dating violence (TDV) can lead to health problems for those involved, especially females, including homicides and is predictive of intimate partner violence in adulthood. Methods: To analyze the adolescents' perception of definitions, justifications and consequences of TDV, a qualitative study through 13 focus groups with 132 high school students from public and private schools of Rio de Janeiro city, including 70 girls and 62 boys was conducted. We followed a guide with questions about interpersonal violence and participants completed a self-administered questionnaire on socio-demographic data. The data analysis included reading and comprehension of the textual data; coding of the reports according to the emerged categories; identification of the meanings attributed by the subjects to the questions raised; comparative dialogue with literature; and elaboration of interpretative synthesis. Results: Most adolescents affirmed that TDV is not justifiable. However, in practice, they found it acceptable in certain situations. The narratives of the boys were based on the role of the perpetrator and the girls on that of the victim. Violence occurs when the man feels his power challenged and is influenced by situations of violence experienced in his own family as victims or witnesses. The TDV consequences are for the women and include, in addition to physical and psychological damage, relational problems in other spheres such as family, friends and school. The experience of violence was more common among public school students. Conclusions: The adolescents’ narratives reflect the gender patterns of society in which violence results from inequality of power. The data of this study offer subsidies to policies on TDV prevention and its consequences. They can contribute to training primary care professionals to identify on clinical consultations signs and symptoms of violence and to develop interventions to reduce the health problems of victims.