Schools benefit from principals who can empower, motivate, and support stakeholders in providing high quality learning opportunities and accepting responsibility for improved academic results. Nurturing this sense of professional competence and accountability is difficult, often requiring fundamental changes to the learning culture of a school. A growing body of evidence underscores a significant and positive relationship between principal leadership and student learning and achievement. In-depth study of a principal's leadership, within the context of a highly challenged, high-performing elementary school helped to deepen the understanding of specific instructional and/or transformational behaviors and practices that instigated and sustained organizational change efforts where they were needed most. This qualitative study sought to understand how the principal of a high-achieving urban elementary school facilitated and managed fundamental changes in the schools learning culture. The study investigated one urban elementary school's efforts to implement a structured, school-wide educational reform focused on improving learning results for all students at the school. The researcher examined the reforms through case study methods, employing critical incidents interview techniques, individual and focus interviews, observations of key reform-focused meetings and activities, and analysis of various relevant artifacts. Focus groups with teachers, individual interviews with the principal and 12 additional stakeholders from across the school, observations, and document analysis comprised the main sources of data in this study. The researcher used constant comparative method to analyze the data gathered and determine emerging categories, themes, and patterns. Findings suggest how the principal of a now high-achieving urban elementary school reinvented her role as principal, instituted new norms of collaboration, ensured universally high expectations for all, and provided data-informed, job-embedded professional development, as means to overcome obstacles and improve student outcomes and achievement. Now more than ever, urban principals are challenged to understand and apply these key leadership behaviors and practices in order to build productive learning cultures for teachers and students at their schools.