Thirty-six successive adult patients with lymphoblastic lymphoma entered a study of sequential chemotherapy consisting of an intensive LSA2-L2-type protocol to induce first complete remission. Eighteen patients in first CR (median age 22 years, range 15-51), underwent autologous bone marrow transplantation after receiving a conditioning regimen consisting of cyclophosphamide and total body irradiation. Of these 18 patients, 2 were in stage III and 16 in stage IV; 15 showed mediastinal and 9 bone marrow involvement at diagnosis. The transplant procedure was well tolerated and no treatment-induced deaths occurred. At this time, 14 out of 18 patients are alive and well between 1 and 60 months post transplant (median follow-up time 46 months) with an actuarial disease-free survival of 74%. This phase II study suggests that high-dose chemo-radiotherapy followed by autologous bone marrow transplantation may improve long-term disease-free survival in advanced stage adult lymphoblastic lymphoma.