Background: In patients with coronary artery disease (CAD), regardless of their diabetes status, both hypoglycemia and hyperglycemia are unfavourably associated to cardiovascular events. According to the results of numerous research, both diabetic and non-diabetic patients with ST-elevation myocardial infarction (STEMI) frequently experience hyperglycemia, which is linked to a higher risk of in-hospital morbidity and mortality. Objective: In patients undergoing elective percutaneous coronary intervention (PCI), the goal of this study is to evaluate the association between elevated pre-procedural random blood glucose levels and peri-procedural myocardial injury. Patients and Methods: 110 patients with chronic coronary syndrome who underwent elective PCI at Ain Shams University Hospitals' Cardiology Department. made up this cohort study. They were split into two equal groups, 55 were hyperglycemic and the rest 55 were euglycemic. Prior to the procedure, cardiac troponin (I) and blood glucose levels were assessed. Blood samples for cardiac troponin were then collected 12 hours later Results: Regarding the incidence of myocardial injury and infarction, there were statistically significant difference between the 2 groups, with the incidence of both conditions being greater in the hyperglycemic group (P-value = 0.001, 0.022 respectively). All five individuals with myocardial infarction had higher blood sugar levels. 23 patients belonging to the hyperglycemic group had myocardial injury. On the contrary only 7 patients with myocardial injury belonged to the euglycemic group. The cut-off point of blood glucose level at which myocardial infarction occurred was 166 mg/dl with 100% sensitivity and 72.4% specificity, and that at which myocardial injury occurred was 130 mg/dl with 76.7% sensitivity and 62.5% specificity. Conclusion: We draw the conclusion that patients undergoing elective PCI are more likely to experience peri-procedural myocardial damage and infarction when their pre-procedural plasma glucose levels are excessively high, regardless of their diabetes status.