The best management of asymptomatic carotid artery disease in patient who needs coronary bypass remains controversial. We report the neurological outcome of four patients with asymptomatic unilateral significant carotid artery disease who underwent conventional coronary bypass without carotid revascularization. Our review highlighted the risk of perioperative stroke is not increased despite carotid revascularization was not performed. Asymptomatic carotid artery disease is not the cause for cerebral infarct but soft aortic atheroma encountered during surgery is the main culprit.