The purpose of this study was to provide insight into teacher perceptions as to if and how professional learning communities (PLCs) promote and support effective professional development in a rural high school. Effective professional development should enhance pedagogy, which is defined as improving educational practices of teachers through opportunities that increase knowledge and improve skills (No Child Left Behind, 2001, Section 9101). A case study approach and qualitative data collection methods were selected for the study due to the real-life context in which the inquiry occurred. Data collection began with surveys in order to acquire a broad view of teachers' perceptions, focus groups provided more specificity to teachers' perceptions, and finally individual interviews afforded the most detailed information. The themes that emerged indicated that collaboration is the most important characteristic of a professional learning community in terms of usefulness, flexibility, and professional growth. Most teachers indicated that due to participation in a PLC they had grown professionally and their students had also benefitted. A major theme throughout participant responses was the need for both job-embedded professional development (PLCs) and traditional professional development (workshops, conferences, etc.). Teachers, administration, and board members of similar rural school districts may benefit from this study by understanding teachers' perceptions of effective professional development that impacts classroom instruction. [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.]