This thesis researches some of the characteristics of social development and of establishing peer relations in the preschool period, as well as the role of a preschool teacher in encouraging social interactions. In particular, I studied peer acceptance and risky peer relations/situations that may occur in the preschool period, as I had observed various behaviours in children and peer un-acceptance already during my mandatory practice in preschool institution. This became the basis for the empirical part of the thesis, which introduces pedagogical approaches that establish a stimulating environment and social interactions among all children. After observing a preschool group and talking with the preschool teacher, I developed and implemented a specific social learning program for the group of preschool children concerned. In doing so, I wanted the program to be suitable for the whole group of children, thus my planning and implementation also consisted of anticipating adjustments and activities to improve the quality of peer inclusion, especially for children who are less accepted among peers. The social learning program was evaluated regularly via journal entries after each activity. I obtained the observations of the preschool teacher and the feedback of the children after the completion of all the activities. This gave me a deep insight into social interactions between the children at the time of the social learning program implementation, with particular focus on the less accepted children. The final summary of all the journal entries, the teacher's observations and the feedback of the children showed the positive impact of the activities; the social interactions among all children were mostly positive and pleasant, while the less accepted children were more involved in the activities and responded mostly positively to them. It can be concluded that the approaches used positively influenced the social interactions between preschool children in the research group.