Between 1985 and 1989, eight children underwent two successive bone marrow transplantations. The initial disease was chronic myelomonocytic leukemia in three patients, chronic myelocytic leukemia in two, acute M7 nonlymphoblastic leukemia in one, sickle cell anemia in one, and thalassemia major in one. The preparation in view of the second grafting included high-dose chemotherapy in all patients, associated with antithymocytic globulin transfusion and total nodal irradiation in three patients. Hematological recovery was similar after both graftings. Infectious complications were not more common following the second graft than after the first one. On the other hand, the rates of rejection and graft-versus-host disease were lower, probably due to a more intensive immunosuppressive therapy. The prognosis of chronic leukemia relapsing after a first graft does not seem to be improved by a second attempt.