Evaluation is a key tool in improving the quality and effectiveness of development co-operation. The Development Assistance Committee (DAC) Working Party in Aid Evaluation is the only international forum where bilateral and multilateral evaluation experts meet regularly. Its Members meet to improve evaluation practice and to learn lessons from development co-operation activities and experiences. A series "Evaluationand Aid Effectiveness" was launched to share selected pieces of work with a broader public. Joint multi-donor evaluations provide opportunities but also create challenges. The collaborative nature of such evaluations requires special attention and handling. This guide sets out the key steps to be taken when planning and implementing multi-donor evaluations. It draws upon experiences encountered in various types of multi-donor evaluations, some of which were conducted by the DAC Working Party on Aid Evaluation, while others were joint evaluations of multilateral agencies such as UNICEF, or more recently the European Commission's aid programmes and UNCDF. Insights have also been gained through joint evaluations by the Nordic countries. A print version of the above report is available free of charge from the Development Co-operation Directorate; please send an email to[email protected]to get a copy.