EN
This contribution deals with the evaluation of cognitive training focused on reduction of aggression among children between the ages 6-10 (N = 137). After instruction and practicing in discussions with children, the teacher asked them questions prepared beforehand and then reinforced only those answers which had features of prosocial behavior. Discussions between teacher and children were focused on reinforcement of accepted prosocial behavior and ignorance of hostile manifestations. Discussions were combined with training methods focused on development of empathy and altruism. Before and after discussions and after application of training methods teachers recorded the frequency of aggressive behavior in the classroom into the questionnaire prepared in advance. We focused our attention especially on six forms of aggressive behavior: physical, verbal and indirect aggression, negativism, resentment and irritability. All observed forms of aggression were statistically evaluated. We recorded statistically significant differences in both measures. Aggressive behavior of children was reduced after teachers' interventions.