Since the late 1990s international state builders have paid increasing attention to fighting corruption in both Bosnia-Herzegovina and Kosovo. On the surface this effort has brought significant results, since both countries have adopted legal frameworks modelled on the best practices of Western democracies. In practice, however, corruption remains rampant. This disappointing outcome has several explanations: in reviewing the empirical evidence we consider the two countries as cases involving heavily assisted transition from both socialism and war, highlighting how collusive practices between political and criminal interests have played a role in establishing formally liberal but substantively ‘hybrid’ institutions. We argue that the spread of corruption has been implicitly legitimised by international actors, who have pressured local parties to accept the formal architecture of good governance, including anti-corruption legislation, while turning a blind eye to those extra-legal structures and practices perceived as functional to political stability.