Factors predicting high functional capacity in old age and 25-year mortality were studied in 1711 men aged 40 to 59 years. The study population was that of the East-West Study, i.e. the Finnish part of the Seven Countries Study. After the 25-year follow-up (in 1984) 766 men were still alive. Nonsmoking and good pulmonary function in earlier middle-age and the absence of coronary heart disease, cerebrovascular disease or emphysema in later middle-age predicted high functional capacity in old age. High systolic blood pressure, low forced vital capacity, smoking, and the presence of coronary heart disease predicted mortality in the next 10 to 25 years. Although mortality rates were higher in eastern Finland, the predictors were similar in both the eastern and the southwestern parts of the country.