Background:Smoking and passive smoking have been identified as variable risk factors for AMI and CAD,smoking plays a major role in premature coronary atherosclerosis and in accelerating atherosclerosisby increasing the oxidation of LDL and damaging coronary endothelial vasodilation. The purpose of this study is toassess coronary atheroscleroticplaque characteristics including (site, extent, nature and length)by computed tomographic angiography in smokers compared to non-smokers.. Methods:This cross sectional, single center study was conducted at atkobri El koba military hospital during the period from December 2019 to July 2021This study included 200 male patients withsuspectedCAD scheduled for coronary CT angiography. They were divided into two equal groups. The first group included smokers and the second group included non-smokers. Results: The smokers' grouphad a significantly higher prevalence of CADcompared to non-smokers' group.There was no significant statistical difference between the two groups regarding number of affected vessel if it was single or multiple vessels.Middle RCA, Left Main artery, Proximal LAD and Mid LAD were more affected among smokers). Comparison of thenature of obstruction showed that therate of obstruction was higher among smokers, as well calcific plaques were the most prevalent type among smokers, however it was more common in non-smokers.Conclusion:Compared to the non-smokers, smokers had a considerably greater prevalence of CAD in our research. The severity of coronary blockage was greater in smokers than in nonsmokers. CCTA is a potential non-invasive method that may detect coronary artery stenosis and rule out coronary artery disease, as well as evaluate the features of atherosclerotic plaques.