Despite randomized controlled trials demonstrating the superiority of carotid endarterectomy over medical management in the prevention of stroke in asymptomatic patients with severe carotid artery stenosis, considerable controversy remains with regard to selecting the appropriate asymptomatic patient for carotid intervention. Adding to the complexity of this issue is the fact that the extensive existing literature on this topic is heterogeneous, with trials having used varying definitions of high-grade stenosis, inclusion criteria for patients, and outcome measurements. The current article will review the existing randomized controlled trials on this topic, data regarding the risk of stroke in asymptomatic patients with severe stenosis, data regarding subsets of asymptomatic patients that may be at a higher-than-average risk of future stroke, and data regarding the efficacy of current medical therapy on the risk of stroke in asymptomatic patients with high-grade stenosis. Ultimately, the challenge for clinicians is to ensure that asymptomatic patients with the highest risk of future stroke are offered carotid revascularization and that the intervention is performed with the lowest possible complication rate, in order to maintain the benefit of prophylactic treatment.