Many countries around the globe are focusing on improving the quality of education for student achievement. In this global pursuit of educational enhancement, Turkey has implemented a School Improvement (SI) programme, specifically demonstrating the importance of change leadership (CL). The current study aimed at examining the optimisation of school components through the SI programme based on CL. We adopted mixed method and longitudinal research by using quantitative (survey) and qualitative (focus group and observation) instruments. Our quantitative findings indicate that the SI programme changed the participants' perspectives on involving themselves in the SI. Participants from experimental schools emphasised that the SI experimental programme improved their capacities to identify and manage areas for SI. Additionally, our findings revealed the importance of parental involvement and leadership practices for the sustainability of SI. Further conclusions and implications are fully discussed.