Recently, research studies and media have reported on the detrimental effects violent video games have on the social behaviors of adolescents. For example, previous studies have found that playing video games is positively associated with aggressive behaviors and negatively associated with prosocial behaviors. However, very few studies have examined the mediating effects of personal characteristics between students playing video games and their social behaviors. Thus, using a sample of 1,242 seventh, eighth, and ninth grade Korean students, the authors aimed to determine how playing video games is related to aggressive and prosocial behaviors and whether the emotional competencies of adolescents, such as empathy, emotional regulation, and behavioral self-control, mediate this relationship. The results indicated that violent video games have a significant direct effect on aggressive behaviors, and a significant indirect effect on prosocial behaviors. Specifically, empathy and behavioral self-control were found to mediate the relation between playing violent video games and prosocial behaviors. These results suggest different prevention and intervention approaches to reduce aggressive behaviors and increase prosocial behaviors in students exposed to violent video games. The limitations and implications of these findings are discussed.