Professional learning communities (PLCs) are collaborative teacher groups that focus on learning and continual improvement. Establishing PLCs can be a challenging endeavor, especially in smaller schools. Smaller schools employ fewer staff members, limiting opportunities for collaboration. This dissertation examined the implementation of PLCs in schools that have been identified as national model schools that have less than 500 enrolled students. This qualitative study utilized case study methodology in order to explore the intricacies of implementing PLCs in national model schools. The participants of the study included principals who had successfully implemented such communities in their school. The study found that some factors such as building strong relationships, establishing time for teacher collaboration, and effective goal setting were common in national model schools, and were essential in implementing PLCs. [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.]