In this study, aiming to understand the individual and environmental dynamics underlying school adjustment of students in the middle school period, the target was to reveal the direct effects of family support, peer relationships and gender and their indirect effects mediated by school climate and academic success on the school adjustment of students. The study additionally adapted the school adjustment scale developed by the Fast Track project team for middle school students to Turkish and performed validity and reliability studies. The study was completed with data from two groups. The data obtained from the first study group were used for the adaptation study, while the data obtained from the second study group were used to answer the research question. In the research, the data collection tools of the 'school adjustment scale', 'perceived social support scale', 'peer relationships scale', 'school climate scale' and 'personal information form' were used. With the aim of finding the answer to the basic problem in the research, path analysis was performed for data obtained from 474 middle school students. The results of the study revealed that school climate, academic grade, gender, family support and peer relationships have significant direct effects in explaining the school adjustment of middle school students. Additionally, the gender and family relationships variables mediated by school climate, and the peer relationships variable mediated by academic grade, had significant effects on school adjustment.