One hundred twenty two children with non-Hodgkin's lymphoma were studied from January 1966 to December 1975. The first group (1966-1972) did not receive an uniform treatment. The second group (1973-1975) entered in a G.A.T.L.A. protocol consisting of: vincristine-prednisone plus surgery and/or radiotherapy as induction treatment, craniocervical radiotherapy and intrathecal methotrexate as CNS preventive treatment and anti-leukemia (6-mercaptopurine, methotrexate and vincristine-prednisone pulses) or anti-lymphoma (COPP) treatment as maintenance, in a randomized trial. Comparison of survival of the two groups are as follows: series 1966-1972, 22% and 20% at 12 and 24 months of evolution, respectively, and series 1973-1975, 33% and 26% at 12 and 24 months, respectively. After 2 years of complete remission we have not seen any relapse. We conclude that 1) this disease is highly malignant and must be treated with more intensive chemotherapeutic treatment, and 2) there is no difference between antileukemia or anti-lymphoma maintenance treatment, as yet.