Iron deficiency (ID) is prevalent in infants, children and adolescents worldwide due to their high iron requirements during growth, low dietary iron intake and low-bioavailability diet. Low iron status is associated with adverse health consequences throughout childhood. Prevention measures should be initiated early and include iron supplementation of pregnant women, delayed cord clamping at delivery and exclusive breast-feeding for 6 months. Iron needs to increase sharply after the first 4–6 months of life and high iron content of complementary foods is critical. Iron fortification of infant formulas and infant cereals, addition of micronutrient powders to home-prepared complementary foods, or provision of iron drops are the most effective prevention strategies in weaning infants, but early introduction of meat and delayed introduction of cow’s milk are also important. Prevention strategies in older children involve dietary approaches which increase iron content and bioavailability of the diet, and consumption of iron-fortified foods. In areas of extensive ID, iron supplementation may be required. If malaria is prevalent, large supplementation doses should only be given to children with confirmed ID. All interventions to control pediatric ID should be integrated into larger national and global health programs for pregnant women and children, including health education, malaria prevention and deworming. The impact of ID prevention strategies on iron status and the prevalence of ID should be monitored by measuring iron status periodically in the population.