School bullying is a source of growing concern. A number of intervention programs emphasize the importance of a positive school climate in preventing bullying behavior. The aim of the presented pilot study was to examine whether calming background music, through its effect on arousal and mood, could create a pleasant atmosphere and reduce bullying occurrence. On the first week, 56 sixth-grade students from two classes completed a bullying and arousal questionnaire after the big recess on three consecutive days, as a baseline measurement. On the second week, calming background music was played during the big recess on three consecutive days and children completed the same questionnaires. On the final week, music was removed and participants completed the questionnaires again on three consecutive days. Results showed significantly reduced bullying occurrence, lower arousal levels, and higher enjoyment of recess when music was played. Bullying occurrence increased on the third week, though it remained lower than on the first week. Arousal levels returned to baseline level once music was removed. Results suggest calming background music may be used in combination with other intervention actions to create a positive school atmosphere and reduce aggressive behavior.