Abstract Background Major component of ACS, Non-ST segment elevation myocardial infarction (NSTEMI), has more than twice the incidence compared to ST-segment elevation myocardial infarction (STEMI). GRACE (Global Registry of Acute Coronary Events) and TIMI (Thrombolysis in Myocardial Infarction) risk scores are the two most popular prediction models in ACS due to TIMI’s advantage in its simplicity in clinical application and GRACE’s favorable discriminating power. Nevertheless, limited evidence compared the usefulness of these two major risk scores and their association with in-hospital events. Purpose To compare between the predictive ability of GRACE & TIMI risk scores for In hospital outcomes among the NSTEMI patients . Methods This prospective observational study was carried out from 8th march 2020 to 7th March 2022. Total 2152 acute NSTEMI patients were included. Both GRACE & TIMI risk score were calculated. For GRACE score, patients who scored ≤108 points were low risk,109-139 points were medium risk, ≥140 points were high risk . For TIMI scores patients with 0-2 scores were low risk , 3-4 scores were medium risk and 5-7 score were High risk. In Hospital outcomes were defined as the in hospital composite events which includes acute left ventricular failure, cardiogenic shock, arrhythmia & mortality. Results Among the 2152 patients majority were male (73.5%) with mean age of the study population were 58.33 ± .25 years. Mean Grace score & TIMI score of the study population were 137.81±16.38& 3.29±.97 respectively. Most of the patients were categorized in to Medium risk groups by both GRACE & TIMI risk scores , 70% & 51.3% respectively. However, high risk group percentage were higher in GRACE score group(41.3%) in comparison to TIMI score group(10.3%). GRACE score showed better predictive ability than TIMI score for in-hospital outcomes as evaluated by ROC curve( AUC of GRACE vs TIMI, In hospital ALVF:0.89vs 0.59, P<0.001; Cardiogenic Shock 0.72 vs 0.57, P=0.002; Mortality: 0.75 vs 0.59, P=0.002; arrhythmia 0.72 vs0.63, P=0.003). Conclusion GRACE showed better predictive accuracy than TIMI in NSTEMI patients for in-hospital outcomes. The sequential use of TIMI and GRACE scores provide an easy and promising discriminative tool in predicting outcomes in NSTEMI patients , thus improve the identification of high-risk patients.Pic :ROC curve for prediction of ALVFPic: ROC curve for Mortality prediction