Survival, causes of death and hospitalization have been studied in 99 patients with the myelodysplastic syndrome. The median survival of the patients was 702 days, and the 10 year actuarial survival only 10 per cent, which is not significantly better than the corresponding figures in the remission stage of AML. Although MDS-patients who developed acute leukemia had significantly (p less than 0.05) more platelets, they also had significantly (p less than 0.05) more major bleeding as a contributory cause of death than patients who did not develop leukemia. Bleeding seems to be diagnosed only in 12 per cent in vivo, whereas major bleeding is found at autopsy in 38 per cent of the patients. The patients who did not develop leukemia died significantly (p = 0.018) more often of cardiovascular causes. MDS patients spend one sixth of their remaining life in hospital, on an average. This is true both for those who develop leukemia and for those who do not. The terminal hospital stay lasts an average of 24 days, which is comparable to the figure for myeloma.