Purpose The purpose of this paper is to trace the development of school autonomy and accountability and related multiple changes and impacts in key areas of school education in Hong Kong since implementing school-based management (SBM) from 1990s. Design/methodology/approach To explore the evolution and the uniqueness of autonomy and accountability in the Hong Kong school system, the paper begins with an historical account, followed by an evaluation of the effects of SBM as shown in policy documents, local research, international reviews and illustrative findings from a case study. The local and international implications of SBM for research and practice are then discussed. Findings This paper shows the links between school autonomy and accountability by exploring the potential effects of both of these factors on educational management and student achievement, which are increasingly emphasised in educational policies. The investigation shows that the assumed links and effects are not always consistent or empirically supported. The positive effects that school autonomy has on school governance and management, teachers' work, school-based curriculums and student learning are all significant when there is also strong leadership, comprehensive continuous professional development and a positive, collaborative school climate. These key elements work alongside school autonomy to facilitate positive change. Research limitations/implications School autonomy and accountability should be viewed as necessary, but not sufficient, conditions for school improvement and development. Further characterisation of the processes happening in schools is needed to explore the different realisations of school autonomy and accountability. Originality/value This investigation of school autonomy and accountability in Hong Kong provides the international audience with a deeper understanding of the dynamics involved in the development of SBM.