The authors reviewed 92 patients diagnosed as ALL. Age range was 1 to 12 years (x = 5 years), 50 males and 42 females. The patients were classified as high risk, intermediate and low risk according to the following prognostic factors: sex, age at diagnosis, visceromegaly, adenopathy, initial WBC, HB, immunoglobulins, and platelets, FAB morphological classification, and bone marrow response to initial therapy, immunological markers, CNS infiltration and mediastinal mass. The previous factors were analyzed individually and also the results obtained with each risk group according to the treatment applied.