Each year, 11 million patients present in the USA with new symptoms suggestive of obstructive coronary artery disease (CAD). Most undergo stress testing but <10% demonstrate myocardial ischemia. Moreover, up to 60% will have CAD which adversely affects outcomes. Cardiac computed tomography (CCT) is being used increasingly as an alternative to stress testing to rule out obstructive CAD in symptomatic patients, and large cohort studies in asymptomatic patients have identified burden of coronary atherosclerosis as a predictor of major adverse cardiovascular events (MACE). This review article will critically evaluate major clinical studies on the use of CCT in both symptomatic and asymptomatic patients and discuss the lessons for the clinical use of CCT.