The School Leadership (SL) roles for high student achievement (HSA), by and large, have remained less explored in the developing countries, especially in Pakistan. As a result, their roles in high achieving schools are unknown. During my review of research studies about School Leaders, I found gaps in literature in the area of School Leadership for high student achievement. Hence, I explored the School Leadership's (Principal) roles in a high achieving school (HAS) in Karachi, affiliated with the Aga Khan University Examination Board (AKU-EB). I also explored the factors which support and hinder the enactment of School Leadership's role for high students' achievement. Within the qualitative research paradigm, the case study method was employed as the research methodology. Data collection was done over a period of seven weeks, through observation and in-depth interviews with the Principal and selected research participants. Data were also collected on a daily basis through document analysis and reflective journals. My findings show that although the SL under study is performing more than 21 roles, which seem to be mix of instructional and pedagogical leadership (PL) roles, however, majority of the roles prove that she is inclined towards pedagogical and distributed leadership, with a futuristic vision, goals and high expectations, capacity building, capital development and distribution of responsibilities. It also reflects from the findings that the School Leadership plays a significant role both directly and indirectly, through pedagogical and distributed leadership for high student achievement (HSA). Moreover, it was observed that the SL and her determination and commitment as a visionary, supportive leader and facilitator, brought the school to the stage where the school is competing with the most elite schools within Karachi, despite being situated in a marginalized and poorly populated area, according to the SL. Her role as a facilitator, developer and provider of all kinds of resources to support teachers and students has been the key driving force in HSA. As a PL, she has the major responsibility for guiding teachers and students academically, socially, and spiritually, within the safe and peaceful environment of the school. Her prevailing roles of distributing responsibilities and empowering people also show SL's distributed and shared leadership approach. In addition, as a reformer, change agent, and strategic leader, she has been successful in initiating and implementing various reforms within the school in terms of structure, policies, teaching and learning and assessment strategies, according to the requirements of AKU-EB