Compared with coronary artery bypass graft surgery (CABG), similar safety and efficacy have been demonstrated for percutaneous coronary intervention (PCI) with bare metal stents (BMS), except for the inferiority of PCI to CABG for repeat revascularization. Drug-eluting stents (DES) have dramatically reduced in-stent restenosis compared with BMS, and comparable prognoses could be expected in PCI with DES compared with CABG. Nevertheless, the long-term prognostic effect of PCI on major adverse cardiovascular events (MACE) in patients with stable coronary artery disease (CAD) remains uncertain, so the spotlight has been focused on the comparative long-term results of DES and CABG. At the moment, we should know that previous studies have reported only that PCI decreases angina frequency and improves short-term exercise performance in chronic CAD patients, and it effectively reduces the incidence of both death and myocardial infarction (MI) only in patients with acute coronary syndromes. Furthermore, a recent study also describes no advantage in improvement of prognosis including death, MI and other MACE for PCI compared with aggressive medical therapy in stable CAD patients, and for stenotic lesions without evidence of ischemia, the benefit of revascularization is less clear; medical therapy alone is likely to be equally effective. In conclusion, based on these data we should restrain ourselves from lesion treatment by simple PCI for angiographically significant CAD without any objective evidence of myocardial ischemia. (Circ J 2011; 75: 211-217)