The main aim of the study was to examine a potential moderator role of social context in which children are exposed to media (alone, with peers, with parents) in the relationship between the frequency of media use and the frequency of committed peer aggression. The study included 880 elementary school students, which completed the following self-assessment measures: Peer violence among school children questionnaire (Velki, Kuterovac Jagodić, & Vrdoljak, 2012), and Exposure to the media scale (Velki & Kuterovac Jagodić, 2012). A moderation effect of parental and peer social context was found; e.g., social context had a positive effect on decreasing the correlation between watching TV and electronic peer aggression. Peers social context during playing computer games was associated with decrease in physical peer aggression. Browsing the Internet with parents or peers also decreased physical and/or electronic peer aggression. The importance of social context as a protective factor is highlighted in the discussion.