The Ethiopian national bean program traditionally followed conventional approaches in bean improvement for smallholder farmers. The relative effectiveness and efficiency of Participatory Plant Breeding (PPB) compared to conventional approaches is not fully understood. The study was initiated to evaluate participatory plant breeding in bean improvement to disseminate more acceptable and productive bean varieties for poor farmers. The study was conducted in eastern Ethiopia. Breeders and farmer selectors evaluated and then selected lines on-station from a diverse germplasm pool. The breeders followed a conventional approach, while farmers evaluated their selected lines on their farm. The germplasms included bush and climbing beans in its selections. The selection demonstrated that farmers were capable of making significant contributions in identification of superior cultivars within a relatively short period. They effectively evaluated and selected from large numbers of fixed lines. They applied up to 40 distinct selection criteria indicating the complexity of the user needs and production conditions. However, yield tolerance to biotic and abiotic stresses, drought, earliness, marketability, cooking characteristics, seed colour and size and growth habit were considered key criteria. Involving farmers in the selection process had several impacts, not only on farmer perceptions and skill building but also on the formal breeding process, farmer acceptance, farmer production and income, farmer-held diversity, farmer breeding and seed processes, farmer empowerment and costs. A new formal-led breeding scheme incorporating farmer participation is also developed. Lack of an effective seed delivery system and supporting policy is likely to constrain release and rapid dissemination of PPB varieties.