Introduction: Coronary artery disease (CAD) accounts for the major chunk of mortality in diabetes. Coronary angiography or arteriography remains the "gold-standard" technique for diagnosing and evaluating CAD. Materials and Methods: 1000 patients with acute coronary syndrome (ACS), 500 patients who are diabetic, and 500 who are non-diabetic admitted in SSIMS hospital, selected randomly during a period of 1-year. Random blood sugar, fasting blood sugar, and glycosylated hemoglobin (HbA1c) were done in all patients with ACS and were taken up for coronary angiography. Results: Peak incidence of ACS in diabetes was in third and fourth decades as compared to the fifth and sixth decades in non-diabetics. 240 (48%) out of 500 diabetics with ACS and Type 2 diabetes mellitus for 5-10 years. 223 (44%) out of 500 diabetic patients had triple or multivessel disease (MVD) compared to 82 (16%) out of 500 non-diabetics. Out of 1000 patients of both diabetics and non-diabetics with ACS, a total number of vessels involved were 1994, out of which 61.3% are involved in diabetics and 38.6% in non-diabetics. About 233 (46%) out of 50 diabetic patients required coronary artery bypass grafting (CABG) as treatment outcome. Higher the HbA1c levels of > 8.5%, 69.2% had triple/MVD and 191 (73.1%) out of 235 patients who had to undergo CABG had HbA1c levels > 8.5%. Conclusion: ACS in diabetic patients presented earlier in life, the severity and extent of CAD and incidence of MVD was significantly high in diabetics when compared to non-diabetics with ACS. Diabetics with poor control having high levels of HbA1c, more number of coronary vessel involvement, the mode of treatment required in them was CABG.