Abstract:Adolescence is a critical developmental period marked by rapid changes that can increase vulnerability to aggressive behaviour. An empirical study was carried out to investigate the predictive role of psychosocial factors (exposure to media violence, peer delinquency, and perceived parental conflict) on aggressive behaviour among adolescents and to evaluate the effectiveness of psychoeducation in reducing aggressive behaviour. A cross-sectional survey of 363 participants aged 10-20 years (M=12.68, SD=1.4) from five junior secondary schools in Ibadan North LGA, were assessed using psychometrically sound scales. The second phase utilised a pretest-posttest quasi-experimental control group design among 80 participants aged 10-16 years (M=12.68, SD=1.4) from a selected secondary school in Ibadan, to establish the effectiveness of psychoeducation for reducing aggressive behaviour.