Five patients with hematologic malignancies who had relapsed between seven months and eight years after their primary bone marrow transplants were prepared with high dose busulfan/etoposide for second marrow transplanatations from the same donors who had provided the marrow for the primary transplants. The preparatory regimen was well tolerated. All patients engrafted and entered complete remission. Two patients are alive and in continued remission two and ten months after second transplant. One patient died with acute respiratory failure after two months and two patients relapsed again eight and 17 months after second marrow transplantation. The combination busulfan/etoposide may prove to be a suitable preparatory regimen for second bone marrow transplant attempts in selected patients.