Cardiac fluoroscopy followed by a submaximal exercise electrocardiogram was used to evaluate 129 healthy men (average age 49 p 6) for assessment of possible latent ischemic heart disease in an asymptomatic population. Of 108 subjects who completed the exercise protocol, 37 (34%) had at least one fluoroscopically detected calcified coronary artery. Of the 16 subjects with a positive exercise stress test, 13 (81%) had calcification of at least one coronary artery, Thirteen of 37 (35%) with calcification had a positive exercise test. Those with calcification of at least one coronary artery had a ninefold increased risk of a positive exercise stress test (p less than 0.0001). The location of a calcific deposit conferred greater risk of exercise-induced ischemic changes than did multivessel involvement. Forty-seven per cent of men with calcification in the left anterior descending coronary artery had an abnormal exercise electrocardiogram vs. 33% and 16% of persons with left circumflex and right coronary artery calcifications, respectively.