Iron status was assessed using a combination of several biochemical indicators (serum ferritin, erythrocyte protoporphyrin, serum iron, MCV, hemoglobin) in 3,676 apparently healthy children. Children who were 10 months, 2 years and 4 years of age were selected from the population undergoing a free medical check up in a Paris Child Health Center. The prevalence of iron deficiency in children of parents from continental France was 29% in the 10 month olds, 13% in the 2 year olds and 7% in those who were 4 years of age. Corresponding figures in children born of immigrant parents were 50%, 44% and 15% respectively. Iron deficiency anemia was found in 8% of 10 month olds from continental France versus 23% in the other group. Children born of parents from the South Sahara were found to be at high risk for iron deficiency.