Numerous changes occur in adolescence, so there are changes in social relationships between adolescents and parents, adolescents and peers. Adolescent peers become more important and they spend more time with them and are liable to peer pressure. Peer pressure marks the pressure on a young person to behave in a certain way regardless of whether it is in accordance with their values, attitudes, and /or wishes by that person or not. Despite the great importance of peers, they can’t replace parents whose behavior and upbringing can affect the selection of peers and adolescent behavior. The purpose of this research is to examine the correlation between peer pressure and parental behavior with peer violence and to examine the correlation between parental behavior and peer pressure. The purpose of this diploma thesis is to supplement the existing knowledge on peer violence in order to improve prevention programs and to improve the work and understanding of different professions that come into contact with the problem of peer violence. Research participants were adolescents with an age range of 12 to 18 years. The measuring instruments used in this diploma thesis are peer violence questionnaire, questionnaire on parental practice and questionnaire on peer pressure. Data processing was performed using the SPSS statistical package in which the descriptive statistics and the Pearson coefficient for correlation determination. The results of the research showed a significant correlation between peer pressure and committed peer violence, as well as the association of certain parental behavior (parental control and joint decision making) with peer pressure in the area of relations with parents, peers and risk behavior. The relationship between parental behavior and perpetrated peer violence didn’t show, but has shown the association between certain parental behaviors (parental support and joint decision making) with perceived peer violence. Based on the obtained results we can conclude that the phenomenon of peer violence can be influenced by numerous factors, including individual parental practices and peers, which is why it is important to involve parents in preventive programs of peer violence, but also to use the influence of groups and the importance of peers in that age for prevention work among adolescents.