The purpose of this study was to describe the perceived problems that precipitated principal leadership change at the end of the 2008-2009 school year at an upper Midwest middle school and to describe the effects from the perspective of system participants. Using a case study approach, the research focused on the perceived effects of principal leadership change and its impact on the perception of the school's culture and student success. Three sources of data were triangulated and used to answer the research questions: pre-existing data from focus groups facilitated by an external consultant, open-ended interviews with eight participants from within the system, and historical AYP data. All interview participants were permitted to direct their confidential interview in a manner that provided meaning to them and obtained the most valid research results. The use of qualitative research techniques and the constant comparative methodology were utilized to facilitate thorough analysis of data and recommendations for practice based upon study results. Although it did not develop nor expand current theory, this in-depth case study confirms principal leadership best practices and provides valuable insight in regard to the change process and the impact of principal leadership on that process. Change was initiated at the time of the retirement of a principal leadership team with a very traditional style when school accountability was being highlighted due to NCLB. This middle school went on a dysfunctional journey resulting in a second change in principal leadership after only one year. Now, just three years later, the school has done a complete turnaround and has become a model for others to follow. This work will be of particular interest to district and principal leaders needing to facilitate change in their schools or those struggling amidst the change process to gain a better understanding of how principal leadership can impact change on school culture and student success. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]