From May 1981 to June 1989, 84 children with non-B-cell lymphoma (82 lymphoblastic, 1 T-cell immunoblastic, 1 unclassified diffuse lymphoma) were treated in the pediatric department of the Institut Gustave Roussy according to a protocol called LMT81, which was derived from the LSA2L2 protocol of Wollner and modified by the adjunction of 10 courses of high dose methotrexate to improve the CNS prophylaxis. No planned irradiation was performed except in cases of initial tests (2 patients) or CNS (5 patients) involvement and residual mass (2 patients). Sixty patients had mediastinal involvement; for the others, primaries were in the head and neck (7), nodes (2), (sub)cutaneous (4), bone (7), and elsewhere (2). According to Murphy's staging system, there were 2 stage I, 6 stage II, 33 stage III, and 43 stage IV. Among the stage IV patients, 41 had bone marrow involvement, 24 of them with more than 25% blast cells in bone marrow and 19 with blast cells in blood; 7 had CNS involvement. Three patients did not achieve complete remission, 4 died in remission (two measles, one post-transfusion AIDS, one unexplained definitive aplasia) and 13 relapsed at 2 to 29 months (median-13 months). Among the 77 patients without initial CNS involvement, there was only one isolated CNS relapse. With a median follow-up of 57 months (10-106 months), the event-free survival is 75% (SE 2.5) for the 84 patients with a plateau at 29 months, 73% (SE 8) for stage I and II patients, 79% (SE 4) for stage III, and 72% (SE 4) for stage IV patients. Survival was similar in each stage group. Reasons for failure of treatment, however, were different, being toxic deaths in stage II; initial therapy resistance, early relapses, and toxic deaths in stage III; and tumor failures in stage IV. In conclusion, this protocol is efficacious on T and non-T, non-B childhood lymphoma with a low incidence of CNS relapse. A future study will seek to diminish toxicity and long-term sequellae while at least maintaining the same cure rate of patients.