This article presents the findings of a research study examining the impact of creative puppetry activities on aggressive behaviour in preschool children. The aim of creative drama was to allow for experiences that help children understand interpersonal relations, put themselves in another's shoes and see alternative possibilities of behaving or acting in given situations. Play with a puppet in small groups offers children opportunities to establish pro-social peer interactions and learn socialisation skills including solving minor conflicts. The research was conducted with 22 preschool teachers in Slovenian preschools and first grades of elementary schools (including 460 children aged 4-7). The teachers completed a scale of social behaviour for each child in the group before introducing the puppetry activities and after concluding them, i.e. after three months of intense, daily creative work with puppets. The paired difference t-test showed that according to the teachers' assessments after the three-month conduct of creative puppetry activities in the group, the frequency of the occurrence of aggressive behaviour in the total population was diminished, especially in the children who had the lowest scores in the initial assessment.