Previous studies have identified risk factors for short- and long-term outcomes for patients undergoing percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI). However, it remains unknown whether they can be generalized to current PCI practice for a broader cohort of patients. We analyzed the follow-up information (mortality and revascularization procedures) obtained from a nationwide Japanese registry during 1997 of a total of 2,211 patients with AMI who underwent PCI at 143 facilities. Demographic, clinical, angiographic, and procedural variables were submitted to statistical analysis to detect the risk factors of adverse outcomes. In-hospital and 1-year mortality rates were 7.1% and 10.9%, respectively. The most important risk factor for in-hospital death was attempted PCI of the left main (LM) coronary artery. Further independent risk factors for death were left ventricular (LV) dysfunction (ejection fraction </=40%), LM disease, older age, multivessel disease, cerebrovascular disease, and diabetes. The receiver-operating characteristics curve for the predicted probability of death was 0.88, indicating a good ability to discriminate high-risk patients. Independent risk factors for 1-year postdischarge mortality were LV dysfunction, older age, renal failure, multivessel disease, and diabetes. The incidence of the need for repeat PCI or bypass surgery was significantly higher in patients with multivessel and LM disease. PCI is a valuable treatment strategy for a broad spectrum of patients with AMI. However, the mortality for patients with LM disease and poor LV function is still high even using current practice standards.