The aim of this study was to determine outcomes and prognostic features of children with acute lymphoblastic leukemia (ALL) treated with two modified St Jude Children's Research Hospital protocols at Ramathibodi Hospital (1997-2008). Event-free survival rates of the "previous protocol" were 88.3 ± 3.3% and 83.0 ± 3.9% and of the "current protocol" were 89.9 ± 3.4% and 88.0 ± 3.8%, at 3 and 5 years, respectively. Adverse prognostic features were identified only in the previous protocol study, including obesity, presenting leukocytes >100 × 10(9)/L, high-risk group, persistent blasts in a day-15 marrow and sepsis. Sepsis also conferred inferior overall survival rates of patients in both protocols. Steady improvement in cure rate over the past decade has clearly demonstrated the optimal use of treatment protocols and a multidisciplinary approach to implementing pediatric cancer care in Ramathibodi Hospital. Our future challenges are refinement in risk and treatment stratification and reduction of treatment-related toxicities, prioritizing death from infections.