Professional learning communities have been labeled as effective and capable of producing continuous school improvement. Despite the merits and popularity of professional learning communities, they have been shown to be an elusive concept to implement. The problem this study addressed was the inconsistent quality of professional learning communities and the negative impact for students, teachers, parents, and school leaders. This study explored the characteristics of exemplary and non-exemplary professional learning communities through the perceptions of the teachers working within a professional learning community to help address implementation concerns. At the time of this study, research was still needed in the area of professional learning communities to provide insights into why some schools successfully implement and others do not. The qualitative case study was developed to identify characteristics of exemplary and non-exemplary professional learning communities. The overarching question that drove the research process for this study was the following: How do the characteristics of an exemplary professional learning community differ from a non-exemplary professional learning community? By researching this question, the researcher provided insights into how educational leaders can best utilize professional learning communities to improve the profession and learning for students. The insights provided valuable data to help educational leaders make improvements. The comprehensive comparative analysis of the participants' responses revealed four recommendations suggested for parties interested in establishing or maintaining a professional learning community. The four recommendations were to: build "buy-in," cultivate collaboration, foster communication, and provide time. [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.]