Graduation rates and standardized test scores are common indicators to measure student academic achievement. These indicators have revealed a gap between two socioeconomic cohorts of students in kindergarten through 12th grade. Students attending high-poverty schools have lower academic performance than students attending low-poverty schools. As a result, researchers have sought to understand more about principals' leadership styles and behaviors that correlate to high levels of academic achievement. The purpose of this research was to compare teachers' perceptions of their principals' leadership styles and behaviors in high- and low-poverty schools. The site was a large public school district in Florida. Samples for the study were elementary and middle school instructional personnel. Anchored in Burns' transformational leadership theory, this research used the Multifactor Leadership Questionnaire 5X (MLQ-5X) to gather perceptions of principals' engagement with a transformative style of leadership. In conjunction, Hallinger and Murphy's instructional leadership framework served as the foundation for evaluating principals' instructional management behaviors. The Principal Instructional Management Rating Scale (PIMRS) allowed examination of principals' instructional leadership behaviors. Data came from 493 instructional personnel. Independent samples t-test results showed the perceptions of principals engaging in more of a transformational style of leadership were higher for principals in high-poverty schools. Principals' instructional leadership behaviors were significantly higher for high-poverty schools. These results suggest a need for future research to explore how to increase principals' growth by using a transformational leadership style and instructional leadership behaviors to meet the needs of all students to close the achievement gap. [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.]