The purpose of this study was to examine the impact of the implementation of a structured professional learning community model referred to as Learning Team Meetings (LTMs) on teacher practice and student achievement from the perspective of teachers and instructional leaders at high-need schools. To accomplish this purpose, a multi-site case study was conducted at three school sites (an elementary, middle, and high school) all within the same region of one of the largest urban school districts in South Florida. Qualitative research methods, including one-on-one observations, interviews, focus groups, and review of documents were utilized to analyze, contrast, and compare perceptions, beliefs, and assumptions of the participants in the study. The participants included teachers, principals, assistant principals, instructional coaches, and Learning Team Facilitators (LTFs). A total of 20 participants were involved in the study. The conceptual framework for this study is rooted in the guiding principles of organizational learning and effective professional development practices. Professional Learning Communities (PLCs) offer formal structures to provide teachers with learning-enriched, ongoing, job-embedded staff development (Hord & Sommers, 2008). This study focused on one trajectory or type of PLC, and sought to better understand the implementation of an organizational systemic knowledge transfer structure and the impact on teacher practice from the participants' perception. The research design provided thick, rich data, which offered in-depth understandings of the participants' perception, beliefs and assumption about the LTMs' impact on teacher practice and student achievement. Through the research it was determined that participants among all three of the schools sites believed that LTMs were changing teacher practice. Further, the participants at each of the school sites recognized the significance of the LTF and that he or she plays an essential role in the LTMs. The significance of the study, implications of these findings, and recommendations for further research are also presented. [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://www.proquest.com/en-US/products/dissertations/individuals.shtml.]