This is a prospective multi-center study in which patients with aregenerative anaemia were treated with a standardized high dosage regime of an anabolic steroid (oxymetholone, Anasteron). 53 patients were included and divided into two groups according to bone marrow cellularity. Furthermore the hypocellular group was subdivided in order to make comparison with earlier studies possible. In the hypocellular group, the frequency of remission was 56% and the 2-year-survival from the onset of symptoms was 75%. This is longer than in some earlier studies, perhaps because of possible differences in etiology and/or because of the effect of systematic high dosage, long term androgen therapy. Patient selection was minimized and was not considered to be of major importance. Patients with hypercellular marrows, on the other hand, responded poorly to androgens. In this group 63% died of acute leukaemia, which confirms earlier suggestions that this form of aregenerative anaemia, frequently is of a preleukaemic nature.