Background and aims: Prediabetes is associated with an increased risk of developing diabetes and cardiovascular disease. Our objective was to assess the extent and severity of coronary artery diseases (CAD) among prediabetic patients using multi-slice computed tomography (MSCT) coronary angiography. Subjects and methods: Our population included 60 patients with mean age 56.2 ±10.5 years presented by typical chest pain with fasting blood glucose (FPG) < 126 mg/dL and HbA1c ≤ 6.4% and at least one CV risk factor. Any patients with prior history of CV disease or clinical evidence of advanced renal disease were excluded from this study. The extent and severity of coronary artery stenosis were assessed using MSCT coronary angiography. The patients were divided into two groups, prediabetic group (GI) and non-diabetic group (GII). Prediabetes was defined as an HbA1c value of 5.7-6.4%. Results: Prediabetic group had significantly higher number of diseased vessels with higher number of patients having MVD compared to non-diabetic group. HbA1C and FPG were found as independent predictors for both extent and severity of diseased coronary arteries. Conclusion: CAD was more advanced in prediabetic patients compared to non-diabetic patients. Moreover, non-diabetic levels of glucose metabolism evidenced by impaired FBG and increased levels of HbA1C were helpful to predict increased risk for the extent and severity of CAD among our study population.