Background Although the morbidity and mortality of coronary artery disease (CAD) vary widely with race and lifestyle, Japanese CAD patients have been clinically managed according to the guidelines of Western countries. To draft guidelines specifically for Japanese CAD patients, a database that describes how Japanese CAD patients are currently managed and the outcomes of those managements practices is required. Methods and Results Patients diagnosed as having 75% or higher stenosis according to the American Heart Association classification in at least 1 branch of the coronary arteries by cardiac catheterization were enrolled in the study. Of 15,628 patients screened from April 2000 to March 2001, 13,812 of them met the inclusion criteria and were followed up for a mean period of 2.7 years. The incident rate of events was 62.8 per 1,000 patients-year including all-cause mortality of 17.5 and total cardiac events of 47.4 per 1,000 patients-year which is much higher than previous reports in Japan. The incident rate of acute myocardial infarction in this study cohort was 7.5 events per 1,000 patients-year. Conclusion The database provides a large body of information on Japanese CAD patients who have significant coronary atherosclerosis diagnosed by coronary angiography, which will be useful for planning future randomized controlled trials. (Circ J 2006; 70: 1256 - 1262)