A Brazilian sample of 58 patients with acute lymphoblastic leukemia has been prospectively followed up with the objective of evaluating evolution of disease. Age ranged from 6 months to 16 years. Of the 58 patients, 11 were positive and 47 were negative for the ETV6/RUNX1 fusion (previously known as TEL/AML1). After a minimum follow-up period of 57 months, 2 of the ETV6/RUNX1(+) patients had died and 11 of the ETV6/RUNX1(-), for an overall survival of 77.6%. Among the 11 ETV6/RUNX1(+) patients (age range, 2 years to 13 years 7 months), all achieved a complete remission; the average overall survival was 64.2 months and the average event-free survival was 61.7 months. Among the 47 ETV6/RUNX1(-) patients, 4 did not have a complete remission; the average overall survival was of 60.8 months and the average event-free survival was 57.2 months. No significant difference was observed between overall survival and event-free survival, nor in any of the other data comparatively analyzed. The patients had a cure rate similar to that described in literature. In this small sample population, the presence of the ETV6/RUNX1 fusion did not identify statistical difference in prognosis.