The Japanese Coronary Intervention Study (JCIS) has revealed that 17,667 coronary artery bypass grafting (CABG) procedures were performed at 477 facilities during 1997, and this report describes the demographic and clinical characteristics, treatment strategies, and the in-hospital and the long-term outcomes in patients treated with CABG in Japan. A total of 1,862 CABG cases, which corresponded to approximately 10% of the overall CABGs, were selected at random. The mean age was 65 years, and 76% of cases were males. The most prevalent clinical diagnosis was stable angina (54%), followed by myocardial infarction (MI) excluding acute myocardial infarction (AMI) (48%), unstable angina (25%), and AMI (5%). A large proportion of cases had multivessel coronary artery disease: 3-vessel disease (56%) and left main trunk disease (29%). The CABG procedures were emergency in 16%, and 93% of anastomotic sites were patent. In-hospital mortality and MI occurred in 5.1% and 3.5% of cases, respectively. The in-hospital mortality rate for emergency CABG was 12.0%, whereas that for elective CABG was 3.8%. The overall mortality rate during the follow-up period of 2.3 years was 10%. During the follow-up period, MI and angina occurred in 2% and 8% of cases, respectively. Percutaneous coronary intervention (PCI) was performed for 8%, and repeat CABG for 0.8%. In Japan, CABG was performed in patients with multivessel coronary artery disease with extensive risk factors. Angiographically determined success was achieved in 93% and the need for subsequent revascularization was relatively low.