The effect of pretransfusion hemoglobin on transfusion burden, thrombosis, and mortality in thalassemia and myelodysplastic syndrome is unclear. We aimed to study the pretransfusion hemoglobin and erythrocyte transfusion burden and investigate the effects of these variables on each other in real-life in thalassemia and myelodysplastic syndrome. Adult patients with thalassemia and myelodysplastic syndrome who received at least one erythrocyte concentrate unit outpatient at Sanliurfa Mehmet Akif Inan Training and Research Hospital during 1 year were included in the study. The data were retrospectively obtained. Ethical approval was obtained for the study. Ninety-two patients were included in the study. In thalassemia major, pretransfusion hemoglobin ≥ 9 g/dL was associated with a lower median annual number of transfused erythrocyte concentrate units (15 vs. 27) and median annual number of transfusion sessions (11 vs. 14)