Among 109 infants and children from 4 months to 5 years of age from low-income families, hemoglobin concentrations lower than 11 gm/100 ml and hematocrit values lower than 33% indicated iron deficiency anemia, but higher levels did not exclude deficiency. Seventy-nine of the 109 were studied during a three-month screening program. Of these, one third had iron deficiency. When only children under 2 years of age were considered, however, the incidence was slightly more than 50%. A 24-hour food intake history correlated well with the presence or absence of iron deficiency and was a useful instrument for evaluating the adequacy of dietary iron in this population.