In a population study of 70-year-old people in Göteborg, Sweden, a representative sample of 449 men and 524 women was followed for nine years. The prevalence of coronary heart disease (CHD) at age 70 was about 30% in both sexes and did not change up to age 79. Myocardial infarction appeared twice as often in men as in women at age 70 but angina pectoris and ST-T changes on ECG showed no sex difference. Myocardial infarction and probable ischaemia on ECG increased significantly between ages 70 and 79 in both sexes. Half of the men with angina pectoris had a history of myocardial infarction and/or probable ischaemia on ECG criteria compared with 23% of the women. The mortality rate was twice as high in men as in women irrespective of CHD. When CHD was present at age 70 the nine-year mortality was doubled. CHD was shown to be a strong independent risk factor for death also in this age group.