The relation of breathlessness to angina was examined in 7,735 middle-aged British men. Among men who did not report breathlessness, the age-standardized prevalence rate of angina was 4%. In men with mild, moderate or severe breathlessness, the prevalence rates of angina were 16, 29 and 41%, respectively. The association between breathlessness and angina was independent of age or cigarette smoking, with similar relations observed in men who had never smoked. The prevalence of electrocardiograms revealing ischemia increased with the severity of breathlessness, even in men without angina or other evidence of coronary artery disease (CAD) at screening. In men with a low forced expiratory volume in 1 second, the prevalence of angina was also increased, but the association was much weaker than that observed between angina and breathlessness. After a 5-year follow-up, 25% of men severely breathless at screening but without any initial evidence of CAD had developed angina, 5% had had a heart attack (half of these were fatal) and 7% were dead from causes other than CAD. The corresponding rates for men not breathless at screening and without evidence of CAD were: 4% angina, 2.5% heart attack and 2% dead from causes other than CAD. Breathlessness appears to be an early indicator of CAD in the absence of either angina or electrocardiographic evidence of ischemia.