A local concern has been the effectiveness of school improvement efforts such as professional learning communities (PLCs) on student achievement. The results of this study are necessary as policy makers, school districts, administrators, and teachers aim to increase student achievement and the effectiveness of PLCs. The purpose of this study was to investigate the relationship between teacher perceptions of PLCs and the resulting impact on student achievement in Title I elementary schools. The research questions examined teachers' perceptions about PLCs in their school as measured by the Professional Learning Community Assessment (PLCA) and the relationship between student achievement as measured by the Maryland School Assessment (MSA) and teacher perceptions of PLCs in Title I elementary schools that have met adequate yearly progress (AYP) and Title I elementary schools that have not met AYP. A convenience sample of 145 teachers from 11 Title I elementary schools provided responses to surveys. Data were analyzed using an independent t test designed to measure teacher perceptions of the dimensions of PLCs as measured by the PLCA and the impact that their implementation has on student achievement as measured by the MSA. The results indicated there were no significant differences between schools that met AYP and schools that did not meet AYP on teachers' perceptions of each dimension of the PLCA. This study advances social change in that it adds to current research on effective practices related to the implementation of PLCs and their impact on student achievement. Additionally, it provides information that school leaders can use as they plan quality professional development for their school districts and staff. [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.]