Treatment of acute leukemias has made a slow but definite progress. About 2/3 of patients with AML und 3/4 of patients with ALL achieve complete remission with cytostatic chemotherapy. However, about 60-70% of patients with AML and about 50% of patients with ALL relapse usually within the first two years after complete remission. With the introduction of cytokines and differentiating agents into the treatment of leukemia one may expect further improvement of cure rate.