Coronary artery calcification (CAC) was assessed by cinefluoroscopy and its extent was scored (CAC score) in 2,163 consecutive patients undergoing coronary angiography, based on the angiographic and clinical data, the patients were categorized into 8 types of coronary artery disease (CAD). The CAC score was lowest in angiographically normal subjects (0.12+/-0.60) and highest in patients with silent myocardial ischemia (14.31+/-8.61). Risk factors for CAC were advanced age, male sex (at age <80 years), hypertension, diabetes mellitus, and a high grade of organic coronary stenosis. The CAC score in patients with acute coronary syndrome (unstable angina+acute myocardial infarction; 5.48+/-7.42) was significantly lower than that in those with chronic CAD (silent ischemia+stable angina; 9.72+/-8.73; p<0.0001), but was still higher than that in normal subjects or those with vasospastic angina (0.92+/-2.88; p<0.0001). The results indicate that CAC is a manifestation of coronary atherosclerosis and its appearance depends on the pathological type of ischemic heart disease. Fixed stenosis with a slow and chronic process tends to be associated with CAC. The clinical implication of extensive CAC in acute coronary syndrome compared with normal subjects should be further investigated.