The World Bank's health sector projects in Timor-Leste have been among the few operations it has funded in that country that have achieved any sort of positive results. This paper examines the factors underpinning their relative success and considers the wider lessons for the delivery of effective aid in the context of peace-building operations in fragile contexts. We argue that political economy factors played an important role in shaping the relative success of these projects, extending and revising an earlier analysis by Rosser. In terms of wider lessons, we argue for a more political understanding of the determinants of aid effectiveness. Specifically we suggest that aid effectiveness needs to be seen as a function not just of the technical quality of project design and the administrative competence of project managers but also the extent to which there is congruence between donor and local elites' agendas.