We evaluated the short- and long-term clinical outcomes of 326 consecutive patients with chronic renal failure, not on dialysis, who had creatine kinase (CK)-myocardial band (MB) fraction elevation after successful percutaneous coronary intervention in a native coronary artery. Based on peak CK-MB levels measured after intervention, patients were divided into 3 groups: no elevation (group 1, n = 184), 1 to 3 × upper normal levels (group 2, n = 72), and >3 × upper normal levels (group 3, n = 70). Baseline clinical and angiographic characteristics were similar among the 3 groups. Angiographic success was similar among the 3 groups, although there was a significantly higher use of intra-aortic balloon pump in patients who had postprocedural CK-MB >3 × normal values and a higher rate of in-hospital complications, i.e., repeat catheterization, repeat target lesion intervention, pulmonary edema, renal function deterioration, emergency dialysis, and major bleeding complications. At 1-year follow-up, mortality rates were significantly higher in these patients (35.4% vs 22.0% for patients with CK-MB 1 to 3 × normal values and 16.7% for patients without CK-MB elevation, p = 0.007). Multivariate analysis showed that CK-MB >3 × normal (odds ratio 3.04; 95% confidence interval 1.41 to 6.57, p = 0.005) and intra-aortic balloon pump (odds ratio 1.49; confidence interval 1.15 to 1.93, p = 0.002) were independent predictors of late mortality. Therefore, patients with chronic renal failure who had CK-MB elevation >3 × the upper normal limit after a successful percutaneous coronary intervention had a higher incidence of in-hospital complications and a significantly higher mortality rate at 1-year follow-up than patients without CK-MB elevation or with <3 × normal CK-MB elevation.