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 "Evaluation and Aid Effectiveness" was launched to share selected pieces of work with a broader public. This publication is composed of two parts: The Workshop Report, based on the fore-mentioned meeting, highlights the various issues raised, topics of discussion and different feedback systems, and outlines the areas identified by participants as most relevant for improving evaluation feedback. The Background Synthesis Report, intended as a starting point for discussion at the workshop, outlines the main concerns and challenges facing evaluation feedback and the means to address these. The report is based on an analysis of questionnaire results, and a review of previous initiatives in this area. The 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.