Change is hard for all but perhaps more difficult for school leaders and other nonprofit organizations. The role that culture plays in a mission-driven organization can often be an impediment to change. This case uses a unique education institution, St. Martin de Porres School of the Cristo Rey Network, to illustrate the importance of culture in implementing change. It demonstrates how leaders can articulate a vision and create a strategy to change an organization and move toward success. The case focuses on the leadership team of Principal Mike Odiotti and Assistant Principal Judy Seiberlich and how they used cultural change as the key driver to school success. That success was defined by improved academic performance, greater accountability for students, teachers and staff and stronger empowerment of constituents. It includes an overview of how the school's leadership team used data to drive decision making. This case is ideal for MBA students, executives in nonprofit management or school leadership and can be used to illustrate change management, nonprofit leadership, culture change, mission-driven strategy or school leadership. It addresses critical issues that organizations face and provides tools and tactics that can be applied to mission-driven enterprises.