Biofortified crops, bred for improved nutritional quality, can alleviate nutritional deficiencies if they are produced and consumed in sufficient quantities. These varieties can be promoted based on their agronomic performance or based on their nutritional qualities. Quality protein maize (QPM) was the first biofortified crop and has been disseminated in Africa using both approaches. To study their effectiveness, a survey of rural households was conducted in the maize-growing areas of East Africa, comparing communities with access to QPM extension activities to control communities. The results show that a third to one half of the farmers in project communities participated in extension activities in all countries except Kenya. In these communities, familiarity with QPM was high (74-80% of farmers), again except for Kenya (19%), but understanding of their nutritional benefits was much lower (47-55%, with 7% in Kenya). In all countries, farmers evaluated QPM varieties as good or better than conventional varieties (CV) for post-harvest characteristics. For agronomic characteristics, however, QPM varieties scored better than CV in Uganda, about the same in Tanzania, but less in Ethiopia. Adoption patterns differed widely between the countries: in the project areas it varied from 70% in Uganda, 30% in Tanzania to none in Kenya. In the control areas, adoption was only observed in Uganda (45% of farmers). Factors that significantly influenced adoption were farmers’ participation in extension activities, farmers’ agronomic and post-harvest evaluation of QPM vs. CM, and their understanding of the nutritional benefits of QPM. Evaluation for agronomic performance was found to be more important than knowledge of nutritional benefits, thus favoring the first approach. A reliable seed supply was, however, found to be a basic condition for adoption.