One hundred thirty children with acute lymphoblastic leukemia were treated at the oncology unit of a metropolitan hospital at Santiago, Chile, between the years 1975 and 1984. The protocol included vincristine (VCR) adriamycin (ADR) and prednisone (PDN) at the induction fase followed by 6-mcrcapto-purine (purinethol) and amethopterine (Metotrexate®) plus pulses of VCR-ADR-PDN every 3 months; encephalic irradiation by cobalt therapy in doses Of 2.400 rads and intrathecal Metotrexate were used for profilaxis of CNS complications. For a follow-up period of 9 years (median 66 months) total survival rates were 40.9%(standard risk patients 44%and high risk patients 30.7%). The frecuency of CNS relapses was 5.4%and they were always followed by fatal hematological relapses. The Q f 7 400 red'' ar re ' a P ses was 13.6%. Treatment was sustained for 36 months, and relapses occurred at rates ol 2b.&-^ m me first year, 6.6%at the second year and 3.5%at the third year. No relapses were recorded along the fourth follow up yeai. (