Family violence is a social and public health issue across the world for many populations and affects many different types of people, for example, children, women, and vulnerable adults. Adolescents are one of the main victims of this important phenomenon. This article estimates the prevalence of family violence in adolescents and associated factors. The study was carried out in 2012 with a probability and representative sample of 656 adolescents aged between 11 and 17 years who were enrolled at public schools located in the extreme South of the city of São Paulo. The association was tested by the proportion test, Pearson’s chi-square or Fischer’s exact test, and Poisson regression adjusted by robust variance estimation, considering a level of significance of 5%. Among adolescents, 38.9% reported having been victims of family violence. Women were victimized with higher frequency (44.1%). The factors associated with prevalence of family violence were being of the female sex (prevalence ratio [PR] = 1.47; 95% confidence interval [CI] = [1.20, 1.80]) and living only with the father (PR = 1.52; 95% CI = [1.11, 2.08]). The prevalence of adolescents who were victims of family violence is high; however, special attention must be paid to women and adolescents who live only with their father—they were established, in this study, as a risk group. Epidemiological studies of this nature are important to reveal the reality of family violence and to aid the construction of intersectoral public policies to promote health, prevent violence, and foster a peaceful culture.