Carotid atherosclerosis is resoponsible for atherothrombotic brain infarcts. Plaques with an ulcerated cap and overlying thrombus and those with a large lipid core may be more susceptible to distal embolisation and complication during carotid endarterectomy and angioplasty with stenting. Distal embolisation may lead to a variety of new ischemic brain lesions, including borderzone, arterial territorial, and lacunar infarcts. This diversity of the lesion appeared to be correlated with histologic features of the embolic materials (cholesterol crystal with or without other atheromatous components, fibrin, or platelets). This variation in the components of the emboli may determine the size and location of the lodged arteries and feasibility of re-opening and hemorrhagic transformation. Distal protection devices trap and divert many emboli seen with this procedure and therefore effectively prevent cerebral complication. Duplex and MRI of carotid artery may be useful for determining the risks of endovascular intervention within individual patients according to plaque morphology.