A total of 62 patients with high-risk acute lymphoblastic leukemia (ALL) were treated with fractionated total body irradiation, high-dose cytosine arabinoside and melphalan followed by bone marrow transplantation (BMT). Thirty-six patients received allogeneic and 26 autologous BMT. Eight patients were treated in CR1, 36 in CR2 (first relapse occurring on therapy for 32), seven in further CR, 10 in relapse (five early first relapse, four second relapse and one fourth relapse) and one with refractory ALL. Severe toxicity occurred in 26 of the 62 patients (42%) and 14 died (22.5%) from non-leukemic causes. The actuarial event-free survival at 3.6 years was 28% after autologous BMT and 52% after allogeneic BMT with actuarial relapse rates of 62% and 35%, respectively. The results of this pilot study seem promising for this group of poor risk ALL, but the relapse rate remains high after autologous BMT and needs to be improved.