Background: Thalassemia is a common condition in Iraq. More than ten thousand patients registered in Iraq. If well-balanced hypertransfusion regimen to maintain pretransfusion hemoglobin level above the internationally agreed 9.0 gm/ dL could suppress the patients‘ bone marrow and shutdown the hematopoiesis to the extent of not producing any hemoglobin F. Patients and Methods: One hundred well-balanced transfusion-dependant thalassemia patients were evaluated for Hemoglobin F level prior to their scheduled transfusions. Hemoglobin level must have been more than 9.0 gm/ dL to qualify the patient to be entered into this group. All such patients must have showed minimal skeletal changes of thalassemia. Another hundred patients with frank features of thalassemia and poor history of blood transfusion were also enrolled in the study. We aimed at knowing whether HbF is significantly different in the two groups. It could indicate that patients‘ bone marrow could be totally turned off and no abnormal hemoglobin will be allowed to be produced. Results: Seventy nine percent of our enrolled transfusion-dependent thalassemia patients who fulfilled the criteria and were well managed showed correction of their HbF level to near zero! Thirty five percent of the poorly transfused patients also corrected their abnormal HbF level. Conclusions: This study showed that marrow micromilieu could be manipulated in patients with thalassemia in such a way so as to totally shutdown production of abnormal hemoglobin F as a result of provision of normal hemoglobin through blood transfusion. The fact that even one third of poorly transfused patients could show the same results indicates that any degree of transfusion support will have its impact on the marrow.