The purpose of this study was to explore teachers' perceptions prior to the implementation of professional learning communities (PLCs) and after the implementation of PLCs in a large suburban high school. The goal was to provide information that focused on (a) retention and achievement of students, (b) retention of teachers, and (c) teachers' views of leadership. The theoretical framework for the study was based on constructivism, social constructivism, and andragogy theories relating to professional development, which encompasses a community of learners for improving teaching and student learning. This study was a narrative ethnography study that used the face-to-face, open-ended semi-structured interview techniques to collect data from core discipline teachers who were on campus before the implementation of PLCs and who are still employed in this school setting. The large suburban high school where the study was conducted has 190 secondary teachers in a school district consisting of three additional high schools. The sample for this qualitative study included three mathematics teachers, one science teacher, two social studies teachers, and two English/Language Arts high school teachers. The findings presented in the study revealed that PLCs have been successful in teachers' professional development. The model has help to alleviate teachers working in isolation and instead has established collegiality and a shared learning environment for all members of the learning community. The findings that were generated from this research with eight secondary high school teachers revealed that collaboration, sharing, planning, and effective transformational leadership is vital to professional development. The results and findings of this narrative ethnography study revealed that teachers' perceptions and implementation of PLCs do influence the schools' learning environment. The findings of this qualitative study will add to the body of research addressing teachers' perceptions and implementation of the PLC model. [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.]