Although related bone marrow transplantation (BMT) is effective for thalassemia, less than 30% of patients have sibling donors. Here, we report unrelated BMT in nine thalassemic children using a high-resolution HLA typing technique to identify donors. HLA mismatches between donors and recipients were 0, 1 and 2 in 2, 5 and 2 cases, respectively. The results showed that white blood cells, platelets and hemoglobin all returned to normal at various time points, and blood transfusion was eliminated from 13 to 62 days after transplantation. Full engraftment was achieved in eight patients while ABO blood types were replaced with that of donors in five of the six ABO mismatched recipients. Acute skin GVHD was found in seven patients and acute liver GVHD in one. One patient with acute intestinal GVHD eventually developed chronic GVHD. One patient died of pulmonary hemorrhage in spite of having a fully functional graft. We conclude that this is the first successful application of unrelated BMT for thalassemia major in Chinese people and that the results will certainly expand donor resources and greatly enhance the survival and quality of life of thalassemic patients.