The purpose of the study was to gain deeper understanding of the PBIS process in high schools and high school principal perceptions of leadership qualities that enable, and challenge, school-wide change to facilitate PBIS successfully. The study provided an opportunity for high school principals to give a voice to PBIS leadership through sharing their personal experiences leading high schools through the PBIS process. A gap exists in the research regarding experience leading PBIS in high schools; it is important to provide high school principals the opportunity to share their experiences with PBIS while leading in a culture of change. Data were collected from high school principals, who completed a survey and participated in a focus group interview or individual interviews. Survey responses were analyzed using descriptive statistics, while a focus group and one-on-one interviews were coded and analyzed to answer three research questions: How do principals describe the process of initiating, implementing, and institutionalizing PBIS regarding data analysis, staff buy-in and staff engagement, and school culture, and how principals perceive the components of effective leadership to be essential to, and exist in, their practice in the successful implementation of PBIS. I found high school principals value: targeted division support for the PBIS process; collective buy-in and engagement cultivated through empowering teachers, building relationships, fostering a sense of community, and embedding PBIS in daily life; an environment where risk-taking is encouraged; transparency in data sharing and analysis with PBIS, especially in creating plans for support and recognition; and carefully planning the initiative. [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.]