This document discusses the relationship between instructional leadership behaviors of high school principals and teachers' organizational commitment. It analyzes data collected from 441 teachers across 28 high schools in Istanbul, Turkey. The findings show that principals displayed instructional leadership behaviors most in setting and sharing school goals, and least in supporting and developing teachers. Teachers' organizational commitment was low in compliance but medium in identification and internalization. A negative correlation was found between principal behaviors and commitment in adaptation, while a positive correlation was found for identification and internalization. Establishing an organized instructional environment significantly predicted organizational commitment sub-dimensions.