This article addresses the question of whether, or under what conditions, democratic institutions contribute to ‘developmental governance’ in sub-Saharan Africa, in forms such as coherent policy formulation, effective public administration, and limited corruption. While few dispute the desirability for Africa of democracy and good governance in theory, many remain sceptical about whether the two necessarily go together in practice. Using a simple framework informed by the new institutional economics, I analyse the impact of political institutions on governance quality in a sample of 38 sub-Saharan African countries. The main finding is that a combination of democratic contestation and institutional restraints on governments' discretionary authority substantially improves developmental governance. Judged against liberal democratic ideals, Africa's emerging democracies have many shortcomings. Yet the article shows that democratic institutions systematically enhance African states' performance as agents of development.