Budget support has become an increasingly important instrument in the context of a partnership-based approach to development assistance. Compared to traditional modes of aid delivery, it promises greater country ownership, reduced transaction costs, better donor coordination, scaling up of poverty reduction and potentially greater development effectiveness. Based on the contemporary research and evaluation work, as well as broad practical experience, this volume presents a timely and valuable review of key concepts, issues, experiences and emerging lessons relevant to budget support. It will be of great interest to practitioners in aid-recipient countries and international financial institutions, bilateral agencies and civil organizations involved in budget support.