The aim of this study was to assess the safety and benefits of early elective percutaneous coronary intervention (PCI) after successful thrombolytic therapy for acute myocardial infarction. Early elective PCI after successful thrombolysis is controversial, and the optimal time for PCI is elusive. Using data from the Korea Acute Myocardial Infarction Registry from November 2005 to June 2007, a total of 383 patients with acute myocardial infarction who underwent elective PCI within 2 weeks of successful thrombolytic therapy were grouped based on time between thrombolysis and PCI as group 1, <24 hours (n = 81, age 59.5 +/- 10.5 years, 10.9 +/- 7.2 hours); group 2, > or =24 and <48 hours (n = 79, 59.5 +/- 11.6 years, 36.4 +/- 6.8 hours); group 3, > or =48 hours and <72 hours (n = 79, 61.0 +/- 10.9 years, 59.8 +/- 6.8 hours); and group 4, >72 hours (n = 144, 61.7 +/- 12.9 years, 117.8 +/- 48.5 hours). Primary study outcomes included major bleeding, in-hospital death, and major adverse cardiac events (MACEs; cardiac death, myocardial infarction, repeated PCI, and coronary artery bypass surgery) at 1, 6, and 12 months. There were no differences among the 4 groups in baseline clinical characteristics and angiographic findings. There were no differences in the incidences of major bleeding, in-hospital mortality, and 1-month outcomes among groups. Rates of composite MACEs and repeated PCI at 6 and 12 months were significantly lower in patients who underwent PCI within 48 hours of thrombolytic therapy compared with those who underwent PCI later (6-month MACEs: 1.0% vs 9.5%, p = 0.014; 6-month repeated PCI: 0% vs 6.8%, p = 0.028; 12-month MACEs: 4.1% vs 14.9%, p = 0.026; 12-month repeated PCI: 1.4% vs 9.6%, p = 0.034). In conclusion, early elective PCI within 48 hours of successful thrombolytic therapy for AMI appeared safe and more beneficial compared with PCI performed later.