The purpose of this "intrinsic multi-descriptive" case study was to explore how a mathematics curriculum leadership graduate degree program influenced seven participants' views and actions as they transitioned into new mathematics curriculum leadership roles. The mathematics curriculum leadership graduate degree program was a joint partnership between a mid-western school district and a university. The graduate program was designed to support the development of knowledge and competencies related to K-12 mathematics curriculum design, analysis, implementation, and evaluation as well as leadership. Data sources included interviews with the participants in 2005, 2008, and 2011. In addition, the participants wrote journals and responded to writing prompts throughout the three years of the program. Results revealed the mathematics curriculum leadership graduate degree program facilitated the development of specialized knowledge about mathematics curriculum and leadership. The mathematics curriculum leaders changed their views of leadership, how they perceived themselves as leaders, and how they perceived their colleagues' views of them. The mathematics curriculum leaders assumed new leadership roles and responsibilities and the program influenced how they approached situations that required leadership (e.g., conflict and communication with colleagues) as well as challenges. Based on the unique design of the graduate degree program, the mathematics curriculum leaders drew on the support from other participants in the program. [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.]