Background: Around the globe, acute myocardial infarction is the primary cause of congestive heart failure and death.There is currently no rating system in place to predict thrombolytic failure in STEMI patients.The aim of the study was to demonstrate that CHA2DS2-VASc-HS scores would predict missing reperfusion in STEMI patients on thrombolytic therapy. Patients and methods: This is a cross sectional prospective study conducted on 70 patients with ST-segment elevation myocardial infarction who were treated with streptokinase who were grouped into two groups. Group I: STEMI patients with successful thrombolysis (30 patients). Group II: STEMI Patients with failed thrombolysis (40 patients). The CHA2DS2-VASc-HSF score was formulated and Coronary angiography was performed .Gensini score estimation for relative severity of these lesions and compared to CHA2DS2-VASc-HSF score for achieving the aim of the study. Results:There was a statistically significant difference between both group according to CHA2DS2-VASc-HSF and Gensini score There was strong positive correlation between CHA2DS2-VASc-HSF score and Gensini score. The cut-off value of CHA2DS2-VASc-HSF score that can predict failed thrombolytic therapy in STEMI patients was 4 (AUC= 0.93%, CI 95% ranged from, sensitivity=95 %, specificity= 76%) Conclusion:This score may help doctors working in non-PCI hospitals determine the risk of failed reperfusion using a well-documented formula that takes into account a variety of risk factors related to the severity of CAD in STEMI patients.