Introduction: Cardiovascular disease has emerged as a major health burden in developing countries. atherosclerotic disease of the coronary arteries is the most common cause of luminal narrowing there are multiple non atherosclerotic causes to it and the subsequent clinical coronary events. ECG is used to diagnose and predict the culprit artery and also level of occlusion in the culprit artery in patients with myocardial infarction. . We evaluated the set of criteria described by Fiol et al and another set of criteria described by Engelen et al as to how well they predict the level of occlusion in the culprit artery. Aim and Objective To assess the pattern of ECG finding among CAD patient with different severity detected by coronary angiography. Material and methods: This is a hospital based prospective study conducted in SMS hospital, Jaipur with patient of acute coronary syndrome (STEMI) from April 2014 to April 2015. Total number of cases was 100. Patients satisfying inclusion criteria underwent coronary angiogram. Data of patients underwent coronary angiogram were co-related with ECG changes. Correlation of CAG finding and ECG changes was done. Qualitative and quantitative morphologic analysis done and results were interpreted accordingly. Results: Majority of the patients were above the age of 50 years (35%). There were 87% males and 13% females. 34% of the patients had hypertension, 29 % were diabetics, 32% were smokers, 41% were dyslipidemic and 48% of patients of age 55 or above. 74 patients of anterior wall MI had LAD as culprit artery, with 11 patients had additional lesion in the left circumflex and 8 patients in right coronary artery i.e 15% patients had LCx & 11% had RCA. Of 14 patients had two vessels disease and 5 patients had triple vessels disease. 26 patients of inferior wall MI, of 22 patients having right coronary artery as the culprit artery, 3 patients had additional lesion in left anterior descending artery and 2 patients in posterior descending artery. Conclusion: ECG have excellent sensitivity, specificity and exhibits good correlation and agreement with CAG to predict the culprit artery.