Abstract     Background: Q waves on a 12-lead ECG are markers of a prior myocardial infarction (MI). However, they may regress or even disappear over time, and there is no specific ECG sign of a non–Q-wave MI. Fragmented QRS complexes (fQRSs), which include various RSR’ patterns, without a typical bundle-branch block are markers of altered ventricular depolarization owing to a prior myocardial scar. We postulated that the presence of fQRS might be associated with a poorer outcome in patients of acute acute ST Elevation Myocardial Infarction (STEMI). Methods and Results: The study included 255 consecutive patients of acute ST Elevation Myocardial Infarction. After excluding 31 patients, the remaining 214 patients were divided into two groups, one consisting of patients who developed fragmented QRS during hospital stay (GROUP A with 139 patients) and the other group consisting of those who did not(GROUP B with 75 patients). In comparison Q wave appeared in 137 patients (64.01%). In 77 patients who did not develop a Q wave on ECG post MI, fragmented QRS developed in 57 of them (74 %), thus making it a valuable tool in identifying a non-Q wave MI. Significantly increased levels of cardiac biomarkers on presentation and increased rates of post MI angina, congestive heart failure, and major tachyarrhythmias were observed up to 30 days of follow up in patients of group A as compared to group B patients. Conclusion: This study of 255 patients highlighted the usefulness of fragmented QRS in identifying patients at higher cardiac risk with larger areas of ischemic jeopardized or necrotic myocardium, and it can provide very useful information in the risk stratification of acute STEMI patients. It also helps to identify the evidence of infarction in patients without a Q wave on surface ECG. These all features make fragmented QRS an area to explore in the field of electrocardiography in the near future in large randomized clinical trials.