The purpose of this study is to outline the nature of empirical base on transformational leadership in Turkey. The present study included a total of 109 graduate theses conducted on school principals' transformational leadership behaviors between 2000 and 2019 and released in the Council of Higher Education's (CoHE) database. Results revealed that an important body of research investigated the relationship between transformational leadership and job satisfaction and organizational commitment. Authors' suggestions to policymakers and practitioners were often about enabling further in-service training activities and providing school principals with various opportunities to study for a master's degree. Suggestions from quantitative studies echoed the need for conducting relevant studies on different samples and expanding qualitative studies to inquiry into transformational leadership. Results, therefore, mirrored the fact that the empirical base on transformational leadership is lacking in terms of mediator and moderator effects of various variables along with the antecedents and results of transformational leadership.