Adverse childhood experiences (ACEs) have a significant impact on a person's psychological development and predispose them to various harmful consequences in adulthood, such as different forms of aggression. Contrarily, positive childhood experiences (PCEs) operate as protective factors, buffering against the adverse effects of ACEs and promoting adaptive behaviors and psychological well-being. However, the role of PCEs in the relationship between ACEs and aggression remains relatively unexplored. To explore the moderation role of PCEs in the relationship between ACEs and aggression and its different components across sexes in a community sample. A sample of 1541 Portuguese adults answered an online protocol with a sociodemographic questionnaire, the Benevolent Childhood Experiences Scale, the Childhood History Questionnaire, and the Buss-Perry Aggression Questionnaire. ACEs were positively correlated with aggression, including physical and verbal aggression, anger, and hostility, with women reporting a higher prevalence of ACEs and higher levels of anger. Men revealed higher scores in physical and verbal aggression. Furthermore, moderation analyses clarified the moderating effect of PCEs on the relationship between ACEs and aggression in women and between ACEs and anger in both sexes. PCEs attenuate the adverse impact of ACEs, reducing aggression and anger levels. This study stresses the complex interplay between childhood experiences and adult aggression, highlighting the differential effects of ACEs and PCEs across men and women. By clarifying these dynamics, interventions can be tailored to bolster protective factors like PCEs. This will ultimately foster healthier developmental trajectories and reduce the prevalence of aggression in adulthood.