This dissertation is an ethnographic study of the promotion of biofortification, and specifically biofortified sweet potato (OFSP) as a solution to malnutrition in the Mwanza region of Tanzania, a major sweet potato producing area in the country.Through a feminist lens, I examine sweet potato, commonly considered a 'women's crop' in Tanzania, and the campaign to promote its use as entry-points to analyze the intersection between women's dynamic engagement in food-related labour and the gendered, economic and social conditions in which women sweet potato farmers' livelihoods are situated. Funded by private foundations and international agricultural research centres, biofortified sweet potato campaigns targeted thousands of women farmers in several Sub-Saharan African countries in an effort to address malnutrition by increasing the nutrient content of staple, subsistence crops such as sweet potato. My findings show that OFSP promotion reinforced existing normative gendered food production roles as well as scientific, technical interpretations of nutrition, while disregarding how socio-economic and environmental conditions mediate everyday and seasonal dietary practices. A close examination of the research activities and marketing of biofortified sweet potato reveal the inherent gendered and social inequalities embedded in current strategies to address nutrition in agricultural development programs in Tanzania. My research suggests that women's associated labour and varying perceptions of nutrition were under-acknowledged in such campaigns. Analysis of discursive and material networks embedded in OFSP campaigns revealed both the intended and unintended long-term and seasonal, social, economic, health and environmental implications of these campaigns and their oversights on sweet potato producers in Mwasonga village since 2006. As a result, OFSP benefits to the female sweet potato producers in my study remained short-term, uncertain, and dependent on external financing and international partnerships, and on individual farmers' access to economic, social and environmental assets.