Over the last half century, international schools have come to represent an increasingly important sector in the changing global education context. International Baccalaureate (IB) schools in particular, and international schools more generally, can be viewed as specific types of educational contexts for leadership practice. In this article we report the results of a mixed-methods study of instructional leadership practices in IB schools located throughout the world. In the quantitative phase, we analyzed data from a global survey of IB program IB coordinators conducted in 2008. The broad trends revealed by the quantitative analysis were then considered in light of qualitative data obtained through in-depth case studies of five IB World Schools in East Asia. Reference to the qualitative data enabled us to explore how instructional leadership was distributed in these schools, as well as how these leadership practices contributed to smoother student transitions across IB programs. Our combined results suggest that instructional leadership is widely distributed in IB schools and contributes to creating cross-program coherence. The study contributes to research on school leadership by illuminating how instructional leadership is distributed in international schools, a heretofore under-researched domain of educational leadership. (Contains 8 notes, 2 tables, and 1 figure.)