Six cases of constitutional aplastic anemia (Fanconi's anemia), including four boys and two girls who were between 6 and 10 years of age, are presented. Congenital abnormalities were observed in all the patients, especially skin pigmentations, renal anomalies, and growth retardation. The initial symptoms were insidious, mainly related to the anemia. All patients were anemic and thrombocytopenic, but only three were leukopenic. Five cases showed increased levels of fetal hemoglobin, which was marked in two. Bone marrow obtained by aspiration and/or biopsy was hypocellular in all cases. Chromosomal studies showed breaks, ring- or cross-chromosomes, chromosome exchanges, and endoreduplications. Five cases were treated with androgens and a good response was obtained in all of them. Four patients died, and the remaining two are alive and well. The clinical and biological features of these patients are in accordance with those of previous reports. The importance of the androgen therapy is stressed; androgen dependence was observed in all cases.