Congenital dyserythropoietic anemia type I is a rare inherited hone marrow disorder characterized by macrocytic anemia with pathognomonic morphological ultrastructural features in erythroid precursors. The disease is usually not diagnosed in the neonatal period. In a retrospective study of 31 patients we found that 17 were first seen in the neonatal age with significant anemia (birth hematocrit 0.34 ± 0.07); 14 of the 17 infants also had early jaundice. Six infants were small for gestational age and two had syndactyly. Although rare, congenital dyserythropoietic anemia type I should be considered in the differential diagnosis of neonatal anemia.