Backgrounds: Noninvasive parameters derived from echocardiogram, Ambulatory electrocardiogram(ECG) and signal-averaged ECG(SAECG) have predictive ability for risk stratification in post-myocardial infarction(PMI) patients. However, data are lacking in the incidence and the prognostic value of these noninvasive parameters in Korean PMI patients. Objectives: The aim of this study is to reveal the incidence and demonstrate the prognostic value of these noninvasive parameters in Korean PMI patients. Methods: This study included 371 unselected PMI survivors(male: 276, mean age: 60.6짹12.1) who underwent echocardiography, ambulatory ECG and SAECG before discharge. The incidence of (1) abnormal SAECG, (2) premature ventricular complex(PVC) counts >10/hr, nonsustained ventricular tachycardia(NSVT) and VT on ambulatory ECG, and low (40%) left ventricular ejection fraction(LVEF) were studied and used as risk stratification markers for later adverse arrhythmic events defined as syncope, ventricular tachycardia, ventricular fibrillation and/or sudden cardiac death. Results: The incidence of PVC���s >10/hr, NSVT and VT on ambulatory ECG was 16.7%(62/371). Patients who have low LVEF were 12.9%(48/332). 21 of 178 Patients(11.8%) have abnormal SAECG finding. The arrhythmic adverse events were occurred in 4.6%(17/371) of all patients(Mean follow-up: 16.4짹14.1 months). Of 62 patients who had abnormality on ambulatory ECG, 9 patients(14.5%) were suffered from arrhythmic events(p<0.05). Arrhythmic events were occurred in 6(12.5%) among 48 patients with lower LVEF(p<0.05). But, SAECG did not show significant difference. Ambulatory ECG findings has most powerful value for predicting event free survival in patient with or without abnormal ambulatory ECG findings. Conclusion: The incidence of abnormal noninvasive parameters was comparable to those of Western studies and these parameters have significant prognostic value for arrhythmic event risk stratification in Korean PMI.