A 25 year old woman with congenital dyserythropoietic anemia (CDA) Type I is described. Typical morphologic abnormalities of the erytliroid precursors in the bone marrow by light and electron microscopy, marked ineffective erythropolesis and iron loading were present. Globin chain synthetic ratios as well as functional and structural studies on the patient's hemoglobin were normal, ruling out the presence of thalassemia or a mutant hemoglobin which can both give rise to morphologic and clinical features similar to CDA. The laboratory findings on this patient and family members and a brief review of the literature are presented.