We determined the incidence, predictors, and outcomes of persistent renal dysfunction (PRD) following percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI). Among 16 264 patients enrolled in a nationwide registry, we studied patients with AMI who had their estimated glomerular filtration rate at baseline and 1 month later (n = 3606). We used multivariate regression and propensity score (PS)-matched Cox proportional hazards to evaluate the association between PRD and outcomes. Persistent renal dysfunction occurred in 1333 (37%) patients. Significant PRD contributors included old age, low body mass index (BMI), hypertension, Killip class, and the extent of vessel disease. Persistent renal dysfunction was associated with an increased 1-year major adverse cardiac events (all-cause death, myocardial infarction, or revascularization) relative to no-PRD (entire cohort: 6.2% vs 4.5%, hazard ratio[HR] 1.63, 95% confidence interval [CI] 1.18-2.25, P = .003; PS-matched cohort: 7.2% vs 4.9%, HR 1.67, 95% CI 1.08-2.58, P = .022). In conclusion, PRD occurred in approximately one-third of patients with AMI following PCI. It was associated with old age, hypertension, low BMI, initial hemodynamic instability, and extent of vessel disease and was a predictor of worse outcomes at 1 year.