The main goal of this research was to examine gender and age differences in committed and experienced peer violence and to examine the relationship between emotional competence, substance use, and peer violence in adolescents. A total of 255 high school students from the Zagreb, Jastrebarsko, and Karlovac areas participated, of which 168 women and 87 men. Participants were introduced to the Scale of Emotional Regulation and Control - ERIK (Takšić, 2003), selected questions from the European Questionnaire Model (EMQ), and the Questionnaire on Violence among School Children - UNŠD (Velki and Vrdoljak, 2011). Data collection was conducted online via a survey form. The results showed that there is a difference between boys and girls in committed electronic and physical violence, while age differences were not found for committed violence. Furthermore, this study did not identify gender and age differences in peer victimization. The results of examining the association of the examined variables showed that emotional regulation and control were moderately positively associated with physical, verbal and electronic violence. Furthermore, the results indicate a moderate negative association between lifetime prevalence of marijuana use and experienced electronic, verbal and physical violence and lifetime prevalence of tobacco use with electronical experienced violence, with more reported cases of violence followed by increased lifetime prevalence of tobacco and marijuana use. Lifetime prevalence of alcohol use shows a moderate positive association with verbal committed violence and electronical and verbal experienced violence, with more reported cases of violence followed by decreased lifetime prevalence of alcohol use.