Purpose: The purpose of this study was to investigate the predictive effects the level of peer acceptance has on school adjustment variables in preschool children. To fulfill the purpose we answered the questions stated following: Does the level of peer acceptance of children have a predictor effect on the level of school liking? Does the level of peer acceptance of children have a predictor effect on the level of collaborative participation? Does the level of peer acceptance of children have a predictor effect on the level of school avoidance? Does the level of peer acceptance of children have a predictor effect on the level of self-directedness?Method: A relational survey method, whose purpose is to establish the predictive effect the level of peer acceptance of preschool children has on school adaptation variables, was used for this study. 99 children, between the ages of 5 and 6, attending nurseries of governmental primary schools run by The Ministry of Education located in central district of province Denizli, established the sample group for the study. The Picture Sociometry Scale and the Teacher Rating Scale of School Adjustment were used in this study. The Teacher Rating Scale of School Adjustment for 5-6 Year Olds was completed by the preschool teachers. The Picture Sociometry Scale was applied to the children individually by the researchers. Research data was analyzed with SPSS 13.0 package programme. The Pearson Product-Moment Correlation Coefficient and simple linear regression methods were used to analyze the data. Findings: There was a significant positive relationship between the level of peer acceptance and the level of school liking, collaborative participation and self-directedness. As the level of peer acceptance increased so did the levels of school liking, collaborative participation, and self-directiveness. In the same way, in circumstances where children were rejected by their peers, the level of school liking, collaborative participation, and self-directedness decreased accordingly. Another result indicated that there was a significant negative relationship between the level of peer acceptance and the level of school avoidance. Namely, as the level of peer acceptance increased, the level of school avoidance decreased; and vice versa. Results proved that the level of peer acceptance had a significant predictive effect on school adaptation variables individually; school liking, collaborative participation, school avoidance, and self-directedness. According to the results, school avoidance is the most highly predictable school adjustment variable by peer acceptance; following school avoidance are the variables school liking, collaborative participation, and self-directedness. Results and Suggestions: The results illustrate that peer relations of young children carry great importance in terms of school adjustment. Hence, this is the reason why preschool teachers should start peer relation developing activities (social skills activities, cooperative group activities) at the beginning of term, and continue them on a regular basis. Additionally, techniques such as sociometry and observation should be carried out to monitor the structure of the peer relations between children. In terms of future relevant studies to be carried out in Turkey, various variables that could affect school adjustment, other than peer acceptance, should be analyzed. In further studies, the number of children in the sample group should be increased, and the longitudinal studies should be studied in order to assess the long-term effects peer acceptance has on the school adjustment of preschool children.