Early trials of allogeneic bone marrow transplantation (BMT) for homozygous beta-thalassemia and the analyses of results of transplantation in patients less than 16 years old have allowed us to identify three classes of risk using the criteria of degree of hepatomegaly, the degree of portal fibrosis and the quality of the chelation treatment given before the transplant. Patients for whom all three criteria were adverse constituted class 3, patients with none of the adverse criteria constituted class one and patients with one or various association of the adverse criteria formed Class 2. Most patients older than 16 years have disease characteristics that place them in class 3 with very few in class 2. For all the patients with an HLA identical donor we are actually using two Protocols for BMT to whom the patients are assigned on the base of the class they belong to at the time of BMT and independently on the age of the patient. For class 1, class 2 and for class 3 the probabilities of survival and of event-free-survival are respectively of 98% and 94%, 87% and 84%, 100% and 67%. For those patients that were older than 16 years at the time of the transplant, the probabilities of survival are 82% and the probabilities of event-free survival are 79%. Bone marrow transplantation is a new form of radical treatment of thalassemia in those patients with an HLA identical donor.