Background: Coronary artery stenting has become the most important non-surgical treatment for symptomatic coronary artery disease. However, in-stent restenosis occurs at a relatively high rate and this problem has led to the routine use of invasive angiography for assessing stent patency. Objective: The aim of the study is to determine sensitivity and specificity of Computerized Topography Coronary Angiography (CTCA) for evaluation of coronary stent patency regarding its different sites and sizes. Patients and methods: The study population consisted of 40 patients presented for follow up after previous coronary stent implantation within at least 6 months regardless presence or absence of symptoms suggestive of in-stent restenosis. It was carried out at Nasr City Police Hospital in the span of one year from June 2018 to June 2019. The study was approved by the medical ethics committee of Al-Azhar University Hospitals and a written informed consent was obtained from all patients. Results: The current study revealed a good diagnostic accuracy of the MSCT coronary angiography (91.2%). Sensitivity, specificity, PPV and NPV were 88.2%, 92%, 83.3% and 94.3% respectively. We also concluded the higher diagnostic accuracy of ISR in LAD compared to other vessels as well as higher diagnostic accuracy of ISR of proximal stents and stents of diameter > 3mm. Conclusion: It was concluded that the 320-slice CT coronary angiography is a robust test that can be used confidently to diagnose patients with coronary stents and more importantly to rule out significant coronary instent restenosis in patients with high likelihood of having significant ISR.