The Authors studied the HbF in an 8-year-old-girl with Fanconi's anemia. At the admission the patient was anemic (Hb 7,1 g%), thrombocytopenic and leucopenic, HbF was 23% (1,8 g%) with heterocellular distribution. Globin chain synthesis in the peripheral blood displayed an alpha/non alpha ratio of. 1,05. gamma-Chain analysis was performed: at position 136 the gamma G/gamma A ratio was 3:1 at positions 75 threonine was present in the 30% of the chains. The girl was transfused and oximetholone therapy was started. After 2 months of treatment, an increase of the Hb levels was observed. This improvement lasted about 5 months. The amount of HbF remained constant throughout the management. It may be suggested that androgens work only on HbA synthesis while the HbF-producing-cells are irresponsive to the hormonal stimulation.