It has long been recognized that agricultural research should involve the farmers themselves. Participatory agricultural research methods have been developed to help farmers and researchers to identify the most appropriate technologies and techniques for a particular area. However, mainstreaming this collaborative approach within government research institutions and extension services has lagged behind. This book describes the Farmers Research Group (FRG) approach by which a multi-disciplinary research team, extension workers and groups of farmers jointly conduct research on selected topics based on farmers' needs, on farmers' fields. It also documents the process of institutionalizing the approach within the Ethiopian Agricultural Research Systems including universities. Farmer Research Groups reviews the history of participatory agricultural research, particularly in Ethiopia. It introduces cases of research conducted by FRGs in Ethiopia - both successful and less successful - and describes how issues of research quality, technology dissemination, effectiveness and efficiency are dealt with. Finally, it summarizes the lessons learned and indicates how participatory agricultural research might be applied in sub-Sahara Africa. This book is essential reading for agricultural researchers, extension workers and agricultural policy makers in government departments, universities, research institutions and NGOs, as well as students and lecturers studying participatory methodologies.