: As a real-time imaging technique, carotid ultrasonography is gaining popularity among doctors due to its accessibility, low cost, speed, safety, and lack of invasiveness. This study aimed to Determine non-invasive carotid ultrasonography parameters indicative of coronary artery disease by assessing the correlation between carotid artery disease and coronary artery disease using coronary CTA and invasive coronary angiography through cardiac catheterization. Methods: Forty patients were recruited for this prospective research after their doctors sent them to the radiology department of Benha university hospital for coronary computed tomography and carotid ultrasonography due to their suspicion of having CAD. Patients were separated into three groups (n=20 with a single lesion, n=10 with two lesions, and n=10 with three lesions) based on the number of lesions present in their coronary arteries. Carotid ultrasonography, CCT, and ICA, as well as a comprehensive history and physical examination, were performed on all patients. Results: Patients were on average 67.75.54 years old, and 62.5% were male. Patients with two or more coronary lesions had a larger carotid plaque burden than those with a single lesion. Neither the prevalence nor the location of plaques differed significantly across the groups. A cut of level more than 1.33 mm in IMT has an 80% sensitivity and an 87% specificity for predicting the severity of coronary artery disease (P0.001). Conclusion: IMT is the only marker having a substantial predictive value in individuals with coronary artery disease. The prevalence of coronary lesions increases with increasing Intima-media thickness diameter.