Lymphoblastic lymphoma (LBL) in adult patients is recognized as a particular entity in the high-grade non-Hodgkin's lymphoma (HG-NHL) group with characteristic clinical and prognostic features. Initially, polychemotherapy normally used in HG-NHL failed to produce long-term relapse-free survival because of progression disease in the CNS and in the bone marrow. Subsequently, the intensification of therapy using multimodality aggressive acute lymphoblastic leukemia (ALL) treatments led to an increase in long-term relapse-free survival. We analyzed retrospectively 53 adult patients with LBL according to the Kiel classification and the criteria by Nathwani et al. Therapeutic modifications depended upon the different times of diagnosis. Twenty-one patients received the modified L17 regimen, 13 patients were treated with the L0288 regimen, and 19 patients were submitted to the L20 protocol. There was no significant differences in CR rates among the three protocols: 48% vs 54% vs 63%, respectively. Nineteen of 29 patients who achieved CR were alive and relapse-free at a median follow-up of 84 months. Ten of the CR patients underwent autologous bone marrow transplantation (ABMT) to consolidate the first response and 7 of them are alive and relapse-free. Early stage of disease, age < 30 years, low LDH levels, the absence of leukemic phase at diagnosis, and, in particular the attainment of CR were all features of patients with good prognosis. Our study confirms the role of intensive polychemotherapeutic regimens including CNS prophylaxis, the significance of a score model of prognostic factors, and of the role of ABMT (or allogeneic bone marrow transplantation) in the treatment of adult LBL.