Iron de?ciency is a widespread nutrition and health problem in developing countries, causing impairments in physical activity and cognitive development, as well as maternal mortality. Although food forti?cation and supplementation programmes have been effective in some countries, their overall success remains limited. Bioforti?cation, that is, breeding food crops for higher micronutrient content, is a relatively new approach, which has been gaining international attention recently. We propose a methodology for ex ante impact assessment of iron bioforti?cation, building on a disability-adjusted life years (DALYs) framework. This methodology is applied in an Indian context. Using a large and representative data set of household food consumption, the likely effects of iron-rich rice and wheat varieties are simulated for different target groups and regions. These varieties, which are being developed by an international public research consortium, based on conventional breeding techniques, might be ready for local distribution within the next couple of years. The results indicate sizeable potential health bene?ts. Depending on the underlying assumptions, the disease burden associated with iron de?ciency could be reduced by 19e58%. Due to the relatively low institutional cost to reach the target population, the expected cost-effectiveness of iron bioforti?cation compares favourably with other micronutrient interventions. Nonetheless, bioforti?cation should not be seen as a substitute for other interventions. Each approach has its particular strengths, so they complement one another.