Acute non-lymphoid leukemia is a group of hematologic neoplasms which have been the subject of intensive basic and clinical research. These studies have led to a better understanding of the genetic basis of leukemia and may ultimately help establish the molecular mechanisms of malignant transformation. They also have increased our understanding of myeloid differentiation. As a result of clinical trials, we can now induce a clinical remission in a large majority of patients with acute non-lymphoid leukemia. Future studies will attempt to lessen toxicity and to maximize the response rate. Many of these advances will come from improvements in supportive care given during the periods of therapy-related marrow aplasia. The role of intensive chemotherapy to prolong remission duration and to increase the usefulness of allogenic bone marrow transplantation will be clarified during the next several years.