Budget support is aid provided directly to a partner government's central exchequer, and aims to reduce poverty through helping to fund the poverty reduction strategy of the beneficiary country. DFID's use of budget support has risen to £461 million, representing nearly twenty per cent of bilateral expenditure. This study examines the aims of budget support, what it is achieving, how DFID manages the risks of using it and how DFID takes individual funding decisions. The report finds that budget support has: often enabled partner governments to increase expenditure on priority areas; resulted in partner governments providing more services, particularly in health and education; helped increase the capacity of partner governments to plan and deliver services effectively and to develop better poverty-focused policies; helped partner governments to strengthen their financial management systems and encouraged other donors to support such reforms; facilitated donor alignment to, and support for, the developing nation's own strategies; and reinforced existing economic stability and good economic management. But evidence on whether budget support has yielded better value for money than other forms of aid is not conclusive. While budget support has some advantages compared to other forms of aid, it also carries significant risks which need to be better managed. Monitoring achievement is challenging, and DFID does not always set out what it expects to achieve or by when. Formal monitoring frameworks do not always track progress in remedying weaknesses in financial systems. And monitoring of human rights - one of the key criteria for giving budget support - is not yet systematic. Weaknesses in available statistics continue to limit the ability to monitor results. Developing country governments may not be capable of using UK funds efficiently and effectively or may misuse them for political reasons or through corruption.