Twenty courses of carminomycin were administered to 18 evaluable adult patients with acute leukemia (14 ANLL, 2 ALL, 2 CGL-BC). All but one received daily doses of 6-14 mg/m2 for 5 consecutive days. Two patients older than 60 yr had not prior chemotherapy and the others had refractory or relapsed disease. The median age was 60 yr. Three ANLL patients achieved complete remission for 8, 9 and 9 months respectively, with no maintenance therapy. None of these had proven clinical resistance to daunomycin and/or doxorubicin. Mucositis was dose-related and dose-limiting. Nausea and vomiting were rare. Alopecia was constant. Cardiac arrythmia was ascribed to carminomycin in two patients. One episode of cardiac failure seemed clearly drug-related and recovered with symptomatic treatment. In conclusion, encouraging antileukemic activity was observed with carminomycin in poor-risk patients. At doses up to 12 mg/m2 day X 5, extramedullary toxicity remained acceptable.