Congenital dyserythropoietic anemia (CDA) is a rare disorder, characterized by the association of ineffective erythropoiesis, variable degree of anemia, and erythroblastic morphological abnormalities. alpha-Interferon has been reported to be effective in type I CDA, but efficacy in other types of CDA is uncertain. Encouraged by the reports, we evaluated the efficacy of alpha-interferon in 6 children with CDA. Diagnosis of CDA was established on the basis of clinical profile, distinct morphological findings on light microscopy, and the Ham's test, following the exclusion of the more common causes of hemolysis. Erythrocyte agglutinability and lysis to anti-i and anti-l sera, electron microscopy, and SDS-polyacrylamide gel electrophoresis were not performed, due to nonavailability. There were 3 cases, each, with type I and type II CDA. The mean age was 5.5 years (range: 6 months to 11.5 years). Five of the 6 patients were transfusion dependent. alpha-Interferon was administered subcutaneously for a mean duration of 19 weeks (range: 12-30). The dose ranged from 2.6 to 6.5 million IU/m2/dose. The frequency of injections varied from thrice weekly to alternate days. No favorable effect on hemoglobin, reticulocyte count, or transfusion frequency was observed. alpha-Interferon therapy was found to be ineffective in all the patients. These observations question the use of interferon in CDA until further studies in a larger number of patients establish its efficacy.