92 women aged 60 years and over (mean 82.2, SD 8.6) living in a nursing home and free from overt cancer were followed-up for 5 years. 53 died during this period; necropsy revealed cancer in only 1 patient. Serum total cholesterol at entry ranged from 4.0 to 8.8 mmol/l (mean 6.3, SD 1.1). Cox's proportional hazards analysis showed a J-shaped relation between serum cholesterol and mortality. Mortality was lowest at serum cholesterol 7.0 mmol/l, 5.2 times higher than the minimum at serum cholesterol 4.0 mmol/l, and only 1.8 times higher when cholesterol concentration was 8.8 mmol/l. This relation held true irrespective of age, even when blood pressure, body weight, history of myocardial infarction, creatinine clearance, and plasma proteins were taken into account. The relation between low cholesterol values and increased mortality was independent of the incidence of cancer.