Background: Coronary artery disease is the leading cause of death in industrialized countries and most patients with diabetes die from complications of atherosclerosis. There are limited data describing the presenting characteristics, management, and outcomes of diabetic and nondiabetic patients with an acute coronary syndrome (ACS). Materials & Methods: This is a Prospective Case–Control study. A total number of 100 Acute Coronary Syndrome patients, out of which 50 patients with diabetes was considered as group I and 50 non–diabetic patients considered as group II fulfilling the criteria for inclusion was considered. Results: Most (36.0% vs 40.0%) of the patients were in 5th decade and 6th decade in group I and group II respectively. Male to female ratio was 2.8:1. Majority of the study patients had typical Chest Pain (angina) in both groups. Hypertension was the most common risk factor in both groups, 43(86.0%) in group I and 39(78.0%) in group II. Dyslipidaemia 37(74.0%) and smoking 17(34.0%) were next common risk factors in group I. However, smoking 30(60.0%) and dyslipidaemia 29 (58%) were the next common risk factors in group II. Family history of IHD was present in more than one fifth of the study patients. Smoking was significantly (p<0.05) higher in group II patients. Majority of the patients had regular pulse rate in both groups (p>0.05). The mean pulse rate was significantly (p<0.05) higher in group I patients however, mean systolic and diastole BP were almost consistent between two groups. Regarding the Anterior MI and Antero–septal MI it was 40.0% in group I and 52.0% in group II. Among the NSTEMI/Unstable angina, anterior ischaemia was found almost two third (66.0%) in group I and 76.0% in group II. Inferior ischaemia and anterior ischaemia were significantly (p<0.05) higher in group I and group II respectively. The mean HbA1C and Total cholesterol difference were statistically significant (P<0.05) between two groups. Recovery & discharge, heart failure, atrial fibrillation, 2nd degree heart block, junctional bradycardia, ventricular tachycardia, recurrent angina, asystole and death was statistically significant (P<0.05) between two groups. The duration of hospital stay was 5.94±1.72 days in group I and 5.44±1.89 days in group II, no statistical significant (p>0.05) difference was found between two groups. Conclusion: This study was done to observe the in–hospital clinical outcomes of Acute Coronary Syndrome in diabetic patients in comparison to non–diabetic patients. Diabetic patients with acute coronary syndrome encountered more in– hospital adverse outcome.