This paper presents a research study where just world research was applied to the analysis of aggression at school. Based on the previous findings that characterize the belief in a just world (BJW) as a valuable resource for maintaining positive well-being and assimilating injustice, the present studies test the hypotheses that: 1) personal BJW is positively correlated with subjective well-being; 2) this relationship holds for victims and aggressors alike. Overall, findings were in line with our hypotheses. The stronger the adolescents' endorsements of the BJW, the better their well-being. The pattern of results persists when controlled for neuroticism and extraversion. The implications of these results for further studies on aggression, victimization, and well-being are discussed.