Mentalizing is the ability to represent mental states to navigate the social world. A reduced mentalizing ability is a risk factor for a variety of psychological issues. Several studies indicated deficits in social cognition in bullies and victims, specifically in mentalizing anger. However, only a few studies investigated mentalizing abilities related to both anger and happiness in pre-adolescence. Our study investigated possible differences in the ability to mentalize anger and happiness in preadolescent bullies and victims, compared to a control group. We interviewed 104 preadolescents (44% males; 56% females; M = 13.2 years; SD = 0.82) and administered the Olweus Questionnaire to identify bullies and victims. We applied a narrative approach to investigate the mental state language referred to anger and happiness. The results indicated a reduced ability to mentalize anger in bullies and victims compared to controls. Both bullies and victims tended to consider anger and happiness predominantly as behavioral conditions rather than a state of mind. These results highlight the need to promote effective intervention programs to prevent bullying by enhancing appropriate mentalization of emotions in pre-adolescents.