Between January 1986 and September 1989, 28 patients over the age of 14 years were treated with a combination of mitoxantrone, cytosine-arabinoside (Ara-C) and 6-thioguanine (MAT) at the Kuwait Cancer Control Centre (KCCC). All patients were newly diagnosed cases of acute non-lymphoblastic leukemia (ANLL). Fifty-eight courses of treatment were given as induction and consolidation therapy. The main toxicity was bone marrow suppression. Other toxicities were mainly nausea and vomiting, hepatotoxicity, renal dysfunction and alopecia. In most patients these were mild and tolerable. Complete remission (CR) was achieved in 18 out of 28 (64%) patients. In six patients it was achieved after one course, in 11 patients after two courses and in one patient after three courses. The median survival was 16 months and for those who achieved CR it was 33 months. The actuarial 3 year survival following CR was 43% and the relapse-free survival was 24%. There was little difference in the CR rate for patients below 40 years compared with older patients. However, there was a remarkable difference in survival, with none of the older patients surviving more than 2 years and an actuarial 3 year survival for younger patients of 49%. The study confirms the efficacy of the mitoxantrone-containing combination as a first-line therapy for ANLL.