The purpose of this paper is to examine the relation of the frequency of watching television and playing video games, and the presence of violent contents in them, on the one hand, and direct (physical and verbal) and indirect peer aggression among students on the other hand The respondents were students (N = 501; 51.9% male and 49.1% female) of the seventh and eighth forms of elementary schools in urban and rural areas, of an average age of 13.6. The research was conducted in February 2010 using instruments for the assessment of students' media habits and Direct & Indirect Aggression Scales (Bjorkqvist et al. 1992). The results of the correlation and regression analyses show that students who watch television more often are more likely to manifest physical and indirect violence towards their peers (r=0.15, p < 0.01 and r=0.12, p < 0.01), and those who more frequently watch violent programmes are more likely to manifest all three forms of violent behaviour towards other students (r=0.16, p < 0.01; r=0.24, p < 0.01; r=0.19, p < 0.01). The watching frequency and the amount of violent content are among the predictors of direct (physical and verbal) as well as indirect violent behaviour against peers. Students who more frequently play computer or video games also more frequently manifest physical and verbal violence against their peers (r=0.28, p < 0.01 and r=0.09, p < 0.05). Students who play games involving a significant amount of violence often manifest all three forms of violent behaviour against their peers (r=0.30, p < 0.01, r=0.24, p < 0.01; r=0.13, p < 0.01). The frequency of playing and the amount of violence in games are predictors of physical and verbal violence, while the relation of playing games with indirect violence (lid not appear to be significant. The results of this and other recent research suggest that exposure to violence in the media increases the risk of aggressive and violent peer behaviour in the real world. It must also be stressed that what might at first glance appear as minor statistical effects may in fact, have serious practical consequences, since a large part of the population is exposed to these risk factors.