The appropriate treatment for asymptomatic patients with obstructive coronary stenoses is controversial. The effect of percutaneous coronary intervention (PCI) on the prognosis of such patients is unknown. The present study compared the 1-year outcomes of patients with stable coronary artery disease (CAD) with regard to the presence or absence of symptoms after elective PCI. A total of 1,944 consecutive patients with stable CAD who had undergone elective PCI were studied. They were divided into 2 groups according to symptom status: asymptomatic (n = 1,052) and symptomatic (n = 892). A 1-year follow-up evaluation was conducted by office visit and telephone interview. The end points consisted of all-cause mortality, nonfatal myocardial infarction, and target vessel revascularization. Patients without angina pectoris were older, predominantly men, and more frequently had chronic renal insufficiency, a previous myocardial infarction, a coronary artery bypass graft, and a lower left ventricular ejection fraction. The 1-year mortality rate was greater in the asymptomatic patients (43 [4.1%] vs 16 [1.8%], p = 0.003). The incidence of nonfatal myocardial infarction and target vessel revascularization was similar in the 2 groups (15 [1.5%] vs 12 [1.4%], p = 0.85; and 69 [6.7%] vs 68 [7.7%], p = 0.39, respectively). On multivariate analysis, the absence of symptoms was a strong independent predictor of 1-year mortality (p = 0.017). In conclusion, in patients with stable CAD undergoing elective PCI, the absence of symptoms was associated with an increase in 1-year mortality.