This quantitative study examined the relationships between instructional leadership practices of elementary school principals in high-poverty schools and changes in teachers' ELA instructional practices. This research sought to identify principals' perceptions about their use of instructional leadership practices and the teaching practices used in ELA instruction. The study also investigated the principals' perceptions of the influences of their instructional leadership practices and the changes in teacher pedagogy in ELA instruction. In addition, this research explored the relationships between schools' ESEA designation status and the leadership practices used by principals in their efforts to improve teachers' pedagogy, as well as the leadership practices principals perceived as influencing teachers' pedagogy in ELA. The study used a survey design to capture the perceptions of principals' understandings of which instructional leadership practices influence change in teacher pedagogy in ELA. This study included 220 New York City elementary school principals, of which 95 respondents completed the entire survey. Research questions explored the instructional leadership practices and teacher pedagogy used in ELA instruction that the participants reported as essential for improving teaching practice and student achievement. Descriptive statistics, Spearman's rho correlation, and multiple linear regression analysis were used to analyze the survey data. This study revealed several significant findings. The results of this study have shown that principals believe their leadership practices influence changes in teacher pedagogy. More specifically, teacher development, culture building, and building relationships appear to have the most influence. Another significant finding was that principals of reward, good standing, local assistance plan, and focus schools believe their teachers mostly use research-based teacher instructional practices during ELA instruction. Many of the principals in this study perceived that student misbehavior is a factor in the loss of instructional time. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]