The main purpose of this study was  to investigate how principals in Addis Ababa, contribute to the improvement of academic performance in secondary schools through strategic planning. In an attempt to address this issue, a qualitative case study was conducted in four purposefully selected senior secondary schools. The researcher collected qualitative data through semi-structured interviews with principals, department heads, and supervisors from high-performing and low-performing schools. Qualitative data obtained from the semi- structured interviews were coded and analyzed thematically.The relevant documents were also analyzed. The research result reveals that in schools,principals did not play strategic leadership role in creating and executing strategic plan at school level. The findings also indicate that principals lack strategic leadership skills and knowledge in areas such as conducting a SWOT analysis, defining the vision, mission, and values, setting goals and monitoring implementation. Moreover, there is a lack of coordination between strategic planning and academic performance. As a result, it can be inferred that secondary schools in the study area have not utilized a structured approach in developing their strategic plans based on the context and condition of schools, which included important elements to enhance student academic performance.Based on the findings, the study suggests that secondary schools should have a well-defined policy guideline regarding the strategic planto enhance academic performance. In light of this, the Ministry of Education is advised to create this guideline to effectively support and managing school leaders to improve academic performance.