Scholars have increasingly sought to understand how the process of school improvement differs among schools operating in different school levels, conditions, and contexts. Using Rosenholtz's (1985) conception of "moving" and "stuck" schools as a framework for thinking about school improvement, this study examines the learning outcomes of 39 Hong Kong secondary schools over a 3-year period. We examine whether features of leadership and school capacity differed with respect to these learning outcomes within the sample of moving and stuck schools. This research in Hong Kong has identified several factors that appear to synergistically contribute to differences in patterns of improvement in learning across different subjects in both moving and stuck schools. These factors include resource management of principals and school capacity in terms of professional learning community; workload of teachers; alignment, coherence, and structure; and resource capacity. This study extends the research on leadership and capacity building as a means of school improvement, in the process elaborating on their impact within a non-Western society. (Contains 1 figure, 5 tables, and 3 footnotes.)