A prospective study was made which included 287 infants, 12 months of age and patients of two Vizcaya Health Centers, in order to determine the prevalence of anemia and/or depletion of iron stores. The study design included somatometry and a review of the clinical records, dietary habits and the socio-economic status of the family. Laboratory tests included: hematocrit, hemoglobin, mean corpuscular volume, number of erythrocytes, serum iron, transferrin, iron saturation percentage and serum ferritin. Anemia was present in 9.3% of these children and 6.9% had iron-deficiency anemia. Depletion of iron stores was found in 12.4%. Prematurity, socio-economic status, infants fed low-iron milk, early introduction of cow's milk and the weight at 12 months were all variables that correlated significantly with the anemic or iron deficient states. However, the number of infections during the first year of life did not show a significant correlation. A question about the necessity of routine screening is raised and recommendation is made for iron supplementation in the infants in the high risk group.