To evaluate the efficacies of percutaneous transluminal angioplasty (PTCA) and coronary artery bypass grafting (CABG) for angina pectoris, early and follow-up data were reviewed in 495 patients who had undergone these procedures from 1986 to 1988. In 173 patients with single vessel disease, there were no significant differences in initial success rate and early and late incidences of major complications or cardiac death between 152 patients with elective PTCA and 21 with urgent. When compared in 161 patients with multivessel disease, however, significant differences in success rate were found between 130 patients in the elective PTCA group and 31 in whom PTCA was urgent (81.6% vs. 64.5%, p less than 0.05). Significant differences were also found in early incidence of major complications (3.1% vs. 12.9%, p less than 0.01), early mortality (1.5% vs. 9.7%, p less than 0.01), and the late incidence of cardiac events (6.2% vs. 25.0%, p less than 0.01). These results show that freedom from cardiac death and overall cardiac events in the elective PTCA group as significantly better than that in the urgent group at 42 months of follow-up. Comparing early and follow-up results, on the other hand, there was no statistically significant difference between the elective and urgent CABG groups. Thus, there appear to be limitations on the urgent use of PTCA for refractory unstable angina caused by multivessel disease, and urgent CABG was recommended to high-risk patients of urgent PTCA.