Twelve patients with acute lymphoblastic leukemia in second to fourth remission received allogeneic marrow transplants following preparation with cyclophosphamide, 120 mg/kg and 1400 rad of fractionated total body irradiation. Two patients died of interstitial pneumonitis 32 and 62 days post-transplantation. Six patients relapsed between days 59 and 659 and four died of leukemia-related problems. Two patients who relapsed are currently alive, one in remission and one in relapse. Four patients are alive and free of disease 657 to 991 days following transplantation. This disease-free survival was not significantly better than the six of 22 disease-free survivors previously observed following cyclophosphamide and 1000 rad of total body irradiation given in a single exposure.