The clinical outcome of patients with chronic renal failure (CRF) who undergo percutaneous coronary intervention (PCI) has not been systematically evaluated in a large cohort of patients. We retrospectively analyzed the in-hospital and 1-year clinical outcomes of 10,076 consecutive patients who underwent PCI between January 1994 and December 1997. A total of 95 patients (0.9%) had end-stage renal disease (ESRD) on dialysis, 786 patients (7.8%) had CRF, and 9,125 patients (90.6%) had normal renal function. Despite an angiographic success rate of 97% in all three groups, in-hospital mortality was significantly higher among patients with renal disease, whether they were on dialysis or not, when compared to patients without renal dysfunction (6.8% vs. 4.2% vs. 0.9%; P < 0.0001). At 1-year follow-up, mortality rate was 48.8% for ESRD, 25.7% for patients with CRF, and 5.5%, for patients without renal dysfunction (P < 0.0001). By multivariate analysis, high left ventricular ejection fraction and creatinine clearance were associated with decreased late mortality (OR = 0.84 and 0.95; P < 0.0001), whereas ESRD (OR = 3.65; P = 0.0002), non–Q-wave myocardial infarction (OR = 2.21; P < 0.0001), diabetes mellitus (OR = 1.99; P < 0.0001), and CRF (OR = 1.74; P = 0.003) were independent correlates of increased late mortality. Therefore, PCI in patients with impaired renal function, whether on dialysis or not, is associated with poor in-hospital and 1-year survival. Cathet Cardiovasc Intervent 2002;55:66–72. © 2002 Wiley-Liss, Inc.