Objectives: To determine the association of coronary artery ectasia in terms of its severity and vessels involved in diabetes patients and non-diabetes patients. Study Design: Cross-sectional study. Place and Duration of Study: Department of Cardiology, PAEC General Hospital, Islamabad Pakistan from Jun 2018 to Jun 2020. Methodology: All patients who underwent coronary angiography were included in this study. Two hundred patients (100 patients having diabetes and 100 patients not having diabetes) who presented with chest pain and chest heaviness were diagnosed with coronary artery ectasia on coronary angiography included in this study. Results: Two hundred patients, 100 patients had diabetes, and 100 patients had no diabetes. 71 (35.5%) of the patients were males, and 29 (14.5%) were females. The left anterior descending artery alone was responsible for 23% of Coronary Artery Ectasia, followed by the right coronary artery (16%) in diabetic patients. In patients with diabetes with multiple vessels, the left anterior descending artery and left circumflex artery were most frequently (21%) involved vessels, while left anterior descending and right coronary artery were observed to have Coronary artery ectasia in 16% of diabetes patients. Conclusion: No significant difference in the severity of coronary artery ectasia was noted among diabetes and non-diabetes patients. Left anterior descending was most frequently involved vessels in diabetes patients and right coronary artery in nondiabetes patients. Left anterior descending and left circumflex artery both had coronary artery ectasia in most of the diabetes patients and non-diabetes patients.