Burundi has experienced a significant increase in aid flows in recent years. Currently, about half of the budget is funded by aid, mostly grants. The high external assistance has, however, not yet translated into high and sustainable growth rates. This paper analyzes (i) the policy response of the government to the aid surge and its impact on macroeconomic variables; and (ii) the allocation of external assistance and its implications for growth. Since not all aid affects economic development in the same way, aid disbursements are disaggregated by sector as well as by their lag in impacting growth. The analysis shows that Burundi has mostly spent and absorbed increased aid flows, but has until now not suffered significantly from the possible negative effects of an appreciating exchange rate and the related loss of competitiveness, but the possibility of a Dutch disease effect remains a risk. The country s low growth performance, despite high aid inflows, is not necessarily a sign that aid is ineffective or exceeding Burundi s absorptive capacity. It reflects that a large share of aid has been allocated to either humanitarian and emergency aid or long-run growth enhancing sectors. Therefore, the lagged impact of aid on economic growth is not yet visible. Furthermore, the composition of the domestically financed budget is biased toward recurrent spending, and therefore not directly growth enhancing. In addition, low and often unpredictable aid disbursement ratios aggravate the bias away from investment and toward government consumption. To boost short-term growth, the share of aid allocated to productive sectors, such as agriculture and the supporting infrastructure, needs to be increased. Firm commitments and timely disbursements of aid by donors are essential and the Government of Burundi needs to strengthen its capacity and mechanisms for donor coordination.