Performance of percutaneous coronary intervention (PCI) at centers without cardiothoracic surgery is a contentious issue. Although this practice allows greater access to care, there are safety concerns. The aim was to assess the requirement for emergent coronary artery bypass grafting (CABG) after PCI and characterize patients at highest risk using independent predictors. The study population consisted of 21,957 unselected patients who underwent PCI from August 1994 (Food and Drug Administration stent approval) to January 2008 at a single medical center. Patients requiring emergent CABG (defined as within 24 hours of the index procedure) were identified. Logistic regression analysis was performed to assess for independent correlates of emergent CABG. Emergent CABG was required in 90 patients (cumulative incidence 0.41%). Indications for CABG included triple-vessel disease, dissection, acute closure, perforation, and failure to cross. These patients had significantly higher in-hospital cardiac death rates (7.8% vs 0.7%; p <0.01) and higher rates of Q-wave myocardial infarction, neurologic events, and renal insufficiency. Independent correlates of emergent CABG after PCI were acute ST-segment elevation myocardial infarction presentation, cardiogenic shock, triple-vessel disease, and type C lesion. Risk assessment based on these predictors identified 0.3% of the patient population to have a 9.3% cumulative incidence of emergent CABG. In conclusion, the need for emergent CABG after PCI in the stent era was low and was associated with poor in-hospital outcomes. Risk was nonuniform, with 0.3% of the study population, characterized by acute presentation and complex coronary disease, at heightened risk of emergent surgery.