Iron and zinc malnutrition are major threats to human health and development around the world. The World Health Organization states that over two billion people are affected by iron deficiency. In particular children and pregnant women in developing countries are affected by iron deficiency. A common nutritional base for poor populations is a staple such as maize, wheat, rice, potatoes, cassava, or beans, but many of these have low iron and zinc content as well as potent inhibitors of iron uptake. Nutritional supplements are often unavailable to such populations due to lacking infrastructure, education, and funding. A sustainable alternative to nutritional supplements is to cultivate plants that have a higher content and bioavailability of nutritionally important elements in their edible parts. HarvestPlus is a challenge program whose aim is to develop and distribute new cultivars of staple crops with increased nutritional value. In spite of the discovery of several genes involved in the regulation of iron and zinc metabolism in plants, the key regulators for seed iron accumulation have not yet been described. Little is known about the molecules that are responsible for chelating iron in mature seeds, but the ferritin protein was suggested to be the major iron storing protein in legumes . Both iron and zinc localization, as well as speciation, can have an impact on their nutritional availability. We will present detailed information about iron, zinc, and ferritin distribution in common beans. We used micro-PIXE (Particle Induced X-ray Emission) and proton backscattering analysis to localize and quantify zinc and iron in mature bean seeds. In addition the iron distribution in different P. vulgaris genotypes was studied using Perl's Prussian blue staining. We show that the distribution of iron is dependant on the genotype. Using immunolocalization, we visualized the localization of ferritin in mature common bean seeds. This knowledge can contribute to the discovery of factors that affect the bioavailability of micronutrients and can contribute to breeding common beans with increased nutritional value. The work was supported by HarvestPlus, 2033 K Street, NW, Washington DC 20006-1002, USA and The Ministry of Science, Technology and Innovation, Denmark and the Research Fundation of the University of Aarhus, Denmark. Reference 1. Marentes E and Grusak MA (1998) Iron transport and storage within the seed coat and embryo of developing seeds of pea (Pisum sativum L.). Seed Science Research 8: 367 -375.