Based on evidence gained from ten patients of allogeneic bone marrow transplantation (BMT) and eight patients of autologous BMT, recent knowledge on literatures of BMT and total body irradiation (TBI) is summarized. Interstitial pneumonia after BMT has a strong correlation with TBI. Low dose-rate and fractionation of TBI are seemed to reduce the lung injury, thereby reducing the incidence of nonleukemia deaths. BMT is applied to not only acute leukemia, malignant lymphoma and solid tumors but also to chronic leukemia. It is emphasized that several of the important prognostic factors are within the control of the transplantation team.