The purpose of this qualitative case study was to examine the perceived implications that principal leadership has on transforming a large comprehensive high school into smaller learning communities (SLCs); and to speculate on possible factors that contribute to the change process after the implementation of SLCs. The study explores the roles, responsibilities, and practices of the principal as well as school personnel in a high school setting as they create school-wide change by implementing small learning communities. One over-arching research question was addressed using two sub-questions: What are the perceived implications of converting a large comprehensive high school into small learning communities? A. How does the principal view his role as an agent of change in converting a large comprehensive high school into small learning communities? B. What are school staff members' (i.e., assistant principals, teachers, and SLC grant coordinator) perceptions of the role of the principal as an agent of change in converting a large comprehensive high school into small learning communities? The study considers a conceptual model of organizational learning through the development of social capital. Findings suggest that the participants perceive their role to be one of supporting a vision of achievement that laid the foundation for SLC reform. The vision was based on three guiding principles that established a college-going culture enhanced by SLCs. Study results suggest that the principal attempted to implement the new reforms of SLCs, while maintaining the structures of the large comprehensive high school. A hierarchy of leadership was evident with the principal having the sole responsibility of making the final decisions as they related to school operations. Through their membership on the leadership team, school personnel perceived their influence in the school was exercised in a distributed, yet hierarchical, manner. Ultimately, the principal made all final decisions and is perceived to retain a significant degree of control. Findings also revealed several challenges that hindered effective implementation of SLCs in the school. Budget deficits, scheduling conflicts, and poor planning on the part of the school district prohibited complete execution of the SLC grant proposal. These challenges had a direct impact on expected outcomes of the reform. Failure to completely adopt the reform will prevent stakeholders from fully envisioning many of the promised benefits of SLCs. [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.]