Hereditary anemias caused by &bgr;-thalassemia and sickle cell disease are the most common genetic diseases worldwide. Supportive therapies such as chronic lifelong transfusions, iron chelation for thalassemia, and transfusions or hydroxyurea for sickle cell anemia have significantly ameliorated clinical manifestations of these diseases but cannot eliminate disease and treatment-related complications that result in end-organ damage. Allogeneic hematopoietic stem cell transplantation is the only cure for patients with hemoglobinopathies. Results of transplants have steadily improved over the last few decades due to effective control of transplant-related complications and development of new preparative regimens. Our understandings of mixed chimerism in patients with hemoglobinopathies provide a rationale for the use of less intensive conditioning regimens and gene therapy in these disorders. Although the role of stem cell transplantation for thalassemia major is well defined, few transplants have been carried out in sickle cell disease, and, in light of recent advances, the role of stem cell transplantation in this disease should be revised. This review summarizes the current status of stem cell transplantation for hemoglobinopathies.