The electrocardiograms of 559 persons, 82% of the total population 85 years of age or over in the city of Tampere in 1977-1978, were evaluated according to the classification of the modified Minnesota code. The relative five-year survival rates matched by sex and age were calculated for subjects with various ECG findings. Of the series, 391 persons (70%) died during the five-year follow-up period. The lowest mortality rate was observed in those with no codable change or with minor abnormality in the ECG. Electrocardiographic abnormalities suggestive of ischaemic heart disease were associated with significantly increased mortality. In respect of single ECG changes the greatest mortality rate was found in subjects with atrial fibrillation or first-degree atrioventricular block revealed in the ECG. No increased risk of death was associated with left and right bundle branch block, supraventricular premature beats and ventricular premature beats.