The relation of resting heart rate on biennial ECG examinations to mortality rates over 30 years of follow-up of the Framingham cohort was examined based on 1876 total deaths and 894 cardiovascular deaths, evolving out of 5070 subjects free of cardiovascular disease at entry into the study. In both sexes, at all ages, all-cause, cardiovascular, and coronary mortality rates increased progressively in relation to antecedent heart rates determined biennially. A more impressive association to cardiovascular disease was observed in men than in women, which was independent of associated cardiovascular risk factors. Case fatality rates following coronary events also increased with antecedent heart rate and the fraction of coronary deaths as sudden death increased strikingly with heart rate in men 35 to 64 years of age. There was also a substantial excess of noncardiovascular deaths at high heart rates, and the proportion of all deaths resulting from cardiovascular disease did not increase with heart rate. The excess cardiovascular deaths with more rapid heart rates were also noted, excluding those with interim overt cardiovascular disease, suggesting an effect independent of preexisting cardiac damage.