This study investigated the mechanisms of moral disengagement most commonly used to justify school violence in Sicilian primary school. The main objective of this study was to analyze the mechanisms of moral disengagement that are set in motion by those involved in situations of school violence (victims, aggressors, and bystanders) in Sicilian primary school. Likewise, the differences by gender and age are investigated. A total of 113 subjects in primary school were recruited (56.6% girls). The ages ranged from 8 to 11 (M
= 9.56, SD
= 0.99). The first scale used was the Bullying Inventory by Olweus (1993) in the Italian translation by Genta, Menesini, Fonzi, Costabile, and Smith (1996) and the questionnaire on moral disengagement developed by Caprara, Barbaranelli, Vicino, and Bandura (1996) is also used. The regression analysis showed that the sociodemographic variables and the mechanisms of moral disengagement are different depending on a person’s role (aggressor, victim, or bystander). Moral justification predicted the role of victim in school violence, dehumanization predicted the role of the aggressor (and gender), and the disclosure of responsibility (and dehumanization) predicted the role of the bystander in school violence. The conclusions of this study will facilitate the prevention of school violence, for example, by promoting social integration and minimizing situations of school violence (emphasizing morality, ethics, etc.), thereby establishing balanced and satisfactory interpersonal relationships.