This WHO guideline provides evidence-based recommendations on daily iron supplementation in infants and children, as a public-health intervention for the prevention of anemia and iron deficiency. The recommendation in this guideline is intended for a wide audience, including policy-makers, their expert advisers, and technical and programme staff at government institutions and organizations involved in the design, implementation and scaling-up of programmes for anemia prevention and control, and in nutrition actions for public health. It includes recommendations for iron supplementation in countries where malaria is prevalent.