This study examines the relationship between the academic achievement of students with the instructional leadership behaviors of principals on the base of the mediating role of variables that are instructional climate, school safety, and student engagement. In this research, two-stage sampling method was used. In the first stage, stratified sampling was used to determine the schools in scope of the study. In the second stage, the students and teachers that would participate in the study in those schools were determined randomly. 2601 students and 994 teachers from 35 secondary schools are included in the research in 2016 - 2017 educational year. In this framework, the teachers' perception was referred to determine the instructional leadership and instructional climate level. On the other hand, students' perceptions were used for determining the levels related to school safety and students' engagement. The transition to higher education examination (YGS) of 2017 results was used to determine the academic achievement of students which was the dependent variable of the research. The relationship between independent variables and dependent variables are examined on the base of two-level structural equation model. The results of the research have shown that principals' instructional leadership behaviors have an indirect effect on students' achievement through instructional climate. It has also determined that the principal can make increase the students' engagement and achievement by influencing school safety.