Development results and aid effectiveness have moved to the centre of the development debate and all players are looking at a more results-oriented approach. OECD countries want assurance that they get value for their development donations. In partner countries, citizens are demanding better public expenditure management, including aid allocations, from their governments. Using the Millennium Development Goals as a common yard-stick, both donor and partner countries can measure, monitor and manage aid effectiveness by tracking the results of policies to ensure that they follow a logical chain to reach the desired results. The Development Assistance Committee is working with both its members and partners to improve aid policies and evaluate their implementation in the field. What works and why is examined through discussions with donors and partners to identify and adapt key lessons learned in the areas of accountability, evaluation and reporting for goals such as poverty reduction, public/private partnerships and water and sanitation services. The enormous challenge now will be to optimise these opportunities in order to make the joint efforts of donors and their partners more effective for people in developing countries.