This article examines the problem of bullying among adolescents in secondary schools. The purpose of the study is to analyze the socio-psychological aspects of bullying as a form of deviant behavior in adolescence, as well as to identify the features of its role structure and its relationship with adolescent aggression. The empirical base of the study consisted of 138 students in grades 7–8 from secondary schools in Karaganda, Temirtau and Abai (mean age = 13.5 years). The diagnostic instruments included E. G. Norkina’s Bullying Structure methodology and the Buss–Perry Aggression Questionnaire (BPAQ). The obtained empirical data indicate a pronounced role differentiation within the bullying structure: boys are more likely to occupy the roles of defender and victim, whereas the bystander role predominates among girls. A statistically significant association was found between the initiator role and physical aggression, while the emotional (anger) and cognitive (hostility) components of aggression were relatively independent of role position. Thus, bullying is conceptualized as a structured group phenomenon characterized by a clear distribution of roles. The findings highlight the need to develop targeted prevention programs that take into account not only gender-specific patterns of involvement in bullying, but also the relationship between behavioral aggression and dominant roles.