The proliferation of aid donors and channels for aid and the resulting fragmentation brings about huge costs for developing and donors countries and has a detrimental effect on the impact of aid. Coordination is presented as a strategy to help resolve this problem and has been at the top of the development agenda in the past decade. The EU has on many occasions expressed its ambition to foster this agenda and strengthen internal EU coordination. However, the few existing contemporary studies suggest that the implementation of coordination is fairly low. This article seeks to understand this gap through an empirical analysis of EU coordination in Tanzania and Zambia. The findings reveal that the EU’s internal and external coordination role has indeed been limited. It is argued that challenges to EU coordination can partly be explained by institutional factors, but that ideational and political elements should also be considered in order to gain a more profound understanding. Read more.