Octogenarians have been under-represented in percutaneous coronary intervention (PCI) trials despite an increase in referrals for PCI. As the United States population ages, the number of high-risk PCIs in the elderly will continue to increase. This study investigated the effect of age on short-term prognosis after PCI in 3 age groups. Using the 2000/2001 New York State Angioplasty Registry, we compared in-hospital mortality and major adverse cardiac events (MACEs; death, stroke, or coronary artery bypass grafting) in emergency and elective PCI cohorts across 3 age categories of patients: 10,964 patients who underwent emergency PCI (<60 years of age, n = 5,354; 60 to 80 years of age, n = 4,939; >80 years of age, n = 671) and 71,176 patients who underwent elective PCI (<60 years of age, n = 24,525; 60 to 80 years of age, n = 40,869; >80 years of age, n = 5,782). Patients were considered to have undergone an emergency PCI if they had an acute myocardial infarction within 24 hours, had thrombolytic therapy within 7 days, or presented with hemodynamic instability or shock. Elderly patients had more co-morbidities, including more extensive coronary atherosclerosis, hypertension, peripheral vascular disease, and renal insufficiency, and presented more frequently with hemodynamic instability or shock. In the emergency PCI group, in-hospital mortality (1.0% vs 4.1% vs 11.5%, p <0.05) and MACEs (1.6% vs 5.2% vs 13.1%, p <0.05) increased incrementally by age group. In the elective PCI group, rates of in-hospital complications were considerably lower, with an incremental increase in mortality (0.1% vs 0.4% vs 1.1%, p <0.05) and MACEs (0.4% vs 0.7% vs 1.6%, p <0.05). Age was strongly predictive of in-hospital mortality for emergency and elective PCI by multivariate analysis. In conclusion, elective PCI in the elderly has favorable outcome and acceptable short-term mortality in the stent era. Elderly patients, in particular octogenarians undergoing emergency PCI, have a substantially higher risk of in-hospital death.