In a phase I-II trial, 38 patients with acute myeloid leukemia (AML) were given single drug induction therapy with aclarubicin (ACM) according to two dosing schedules: treatment 1: 10 to 30 mg/m2/d to a maximum total dose of 300 mg/m2 or until development of unacceptable toxicity: treatment 2: 15 mg/m2/d in ten-day courses separated by ten-day intervals. Response rates were 15% with treatment 1 and 44% with treatment 2 (overall response rate 34%). Complete remission (CR) was achieved in 6 patients who had previously failed to respond to adriamycin (ADM). Toxicity was more frequent and more severe in those patients given more than 150 mg/m2 ACM per course. The main side effects were oropharyngeal mucositis and diarrhea. Three patients exhibited T wave inversion and one had an episode of auricular flutter. In a separate trial in 16 patients with AML we used cyclic chemotherapy combining ACM (20 mg/m2/d) and ARA-C (200 mg/m2/d) for seven consecutive days. Complete remission rate was 50%. Severe ventricular rhythm disorders were seen in two patients. In a phase I-II study, 19 patients with acute lymphoid leukemia (ALL) and 8 patients with non-Hodgkin lymphoma (NHL) were given ACM alone according to the regimen designated treatment 1 described above. Response rates were 11% (2/19) in ALL and 25% (2/8) in NHL. A review of the literature is presented in the discussion of the original trials reported herein.