This paper’s objective is to provide a better understanding of the politics underpinning core public sector reforms (PSR) in Rwanda. It analyses five core public sector functions: government coordination, public finance management (focusing on budgeting and public procurement), civil service management, external audit, and anti-corruption policies. For each, it identifies the origins of reforms and analyses to what extent they led to change in both rules and practice. Overall, the paper argues that PSR has been successful and so strongly embraced because rulers considered an effective public sector as a crucial tool for their legitimation strategy, which was based on achieving rapid socio-economic progress and projecting an image of impartiality.