Anemia resulting from severe iron deficiency (ID) is the most prevalent and widespread nutrition-related health problem in infants and young children in low-income countries and has proven very resistant to prevention through public health interventions. Accumulative evidence from animal and human studies suggests that such deficiencies are associated with large adverse effects on child cognitive and motor development. Therefore, effective interventions to improve iron status will have large health benefits. Action to reduce young child ID would benefit from overarching policy and programmatic guidance that informs decision makers about what to do, when to do it, and how to do it. The impetus for new approaches to prevent ID in young children reflects growing recognition of the need to intervene early and often and for better vehicles to deliver iron. Prevention of ID requires strong delivery systems that enhance consumer demand and promote compliance. When this occurs, the prevalence of anemia is greatly reduced.