Sideroblastic anemia is rare in infants. When it occurs, it is generally hereditary and X-linked.A microcytic anemia without iron deficiency was diagnosed in a 2-month old infant with probable acquired cytomegalic infection. Bone marrow examination disclosed ringed sideroblasts without cytomegalic inclusions. Treatment with pyridoxine was tried without effect and no other therapeutic trial was attempted. The child, now aged 5 years, remains well without blood transfusion.Hereditary and acquired sideroblastic anemias may occur in infants and children. Whatever their cause might be, the evolution is unpredictable. The only successful treatment for the hereditary variant remains pyridoxine supplementation which brings relief in about one patient out of three. Efficiency and safety of other therapeutic regimens remain to be proven.