The results of therapy in 100 patients who newly fell ill (68 AML, 32 ALL) with acute leukaemia were evaluated (1981 to 1985). The 5-year-survival chance of all patients is 15% for AML, 18% for ALL, first of all it is depending on the degree of remission obtained. The CR rate is nearly 43% (AML) and 66% (ALL), respectively, shows a dependence upon age and is impaired above all by a high early death rate (supportive therapy). With increasing aggressiveness the results of the remission induction therapy improve, as it becomes clear in a comparison with an evaluation of patients 1965-1980 (CR: 15-32%). Also in the postremission therapy the results of intensive forms of therapy are more favourable: 4 years recurrence-free survival after CR in autologous bone marrow transplantation 50%, in allogenic bone marrow transplantation 40%, in cyclic chemotherapy 17%, in oral permanent therapy 0%. Starting from these findings the present conception of the therapy of acute leukaemias is discussed in connection with the literature.