Today approximately 75 per cent of children with ANLL can be induced into a complete remission and approximately 40 per cent will have an event-free survival for more than 3 years, irrespective of whether they received a bone marrow transplantation or chemotherapy after induction. In order to achieve these results very intensive therapy is required. The morbidity and mortality of treatment are high. The length of therapy needed after induction of remission is not known. Whether or not maintenance therapy is required is perhaps related most directly to the intensity of the therapy employed. Similarly, the role of bone marrow transplantation in patients in first remission, treatment of CNS leukemia, and treatment of chloromas are controversial. There is general agreement that WBCs over 100,000, acute monoblastic leukemia in infants less than 2 years of age, and certain chromosomal abnormalities are associated with a poor prognosis. Although there has been a dramatic improvement in the treatment of ANLL over the past 15 years, stratification of therapy based on biologic parameters, and alteration of treatment based on the early responses to treatment may be required before further advances will be made.