Bone marrow transplantation is the only therapeutic option that can potentially eliminate thalassemic disease. Early results indicated that children in Class 3 Lucarelli had a much worse outcome because of high nonrejection mortality and high rejection rate. In the present study, reduced intensity stem cell transplantation (RIT) was performed in eight Class 3 Lucarelli patients conditioned by busulfan, fludarabine, and antilymphpcute globulin. One of the eight patients additionally received thiotepa, and total lymphoid irradiation (TLI), while one only received TLI. All patients received hydroxyurea 20 mg/kg/day daily >/=3 months before RIT. Peripheral blood stem cell (PBSCs) were given to a target number of CD34(+) cells more than 5 x 10(6) cells/kg of recipient weight. Seven patients received T cell nondepleted PBSCs from matched siblings while one patient received purified CD34(+) cells from two HLA antigen mismatched maternal PBSCs. The graft-versus-host disease (GvHD) prophylaxis included cyclosporine or tacrolimus and mycophenolate mofetil. Initially, an engraftment of donor cells was observed in all eight patients, but subsequently only six of eight patients had stable full donor engraftment. There were no deaths or Grade 3-4 acute GvHD in our patients. The present study lends support that the regimens described here produced minimal toxicity and resulted in stable full donor engraftment in the majority of the severe Class 3 Lucarelli thalassemia patients.