Educational programs implemented during the preschool period, which is a crucial developmental stage, are considered indispensable for fostering social development, enhancing academic achievement, and laying the groundwork for subsequent phases of life. This research aims to conduct a meta-analysis of postgraduate theses conducted in Turkey to ascertain the impact of educational programs that support the social development of preschool children. Additionally, the study seeks to explore how certain characteristics of these research studies, namely publication type, institute, experimental duration, and sample size, may influence the outcomes. The investigation involved a review of postgraduate thesis studies conducted in Turkey, focusing on programs supporting the social development of preschool children. The statistical software "Comprehensive Meta Analysis" was employed to analyze the data, utilizing Hedges'g coefficient. After conducting a literature review, 30 theses that met the inclusion criteria were selected for the meta-analysis study. Combining these studies using the random effects model yielded an overall effect size of 1.08, within a confidence interval ranging from 0.87 to 1.28. The results revealed a positive and strong effect (g=1.08) of educational programs supporting the social development of preschool children. This indicates that such programs have a positive impact on the social development of preschool children. Out of the 62 effect sizes analyzed, seven were found to have negative values. Among the 55 positive studies, five were considered weak, two were small, 14 were medium, and 34 were strong. Furthermore, no significant differences were observed in the effect sizes of the studies when examining the influence of moderator variables related to educational programs supporting the social development of preschool children. Based on the study's findings, alternative education programmes focusing on developing social skills in the preschool period should be emphasised.