#### Summary points #### Sources and selection criteria We search PubMed using the keywords “carotid AND athero* OR stenosis OR plaque”. Key randomised controlled trials and cohort studies were identified. We searched the Cochrane Library using the keyword “carotid”. The UK fourth national clinical guideline for stroke 2012, UK carotid endarterectomy audit round 4, European Society for Vascular Surgery carotid guidelines parts A-C, and European Society for Cardiology fifth guideline on cardiovascular disease prevention were consulted, along with relevant references from these articles. Carotid atherosclerosis is a pathological thickening of the common or internal carotid intima, typically into focal areas known as plaques (or atheromata). Although atheromata can remain stable for many years, surface rupture of unstable (vulnerable) plaques leads to local thrombus formation, with subsequent embolisation to the ipsilateral ophthalmic, middle cerebral, or anterior cerebral artery territories. The resultant symptoms are ipsilateral amaurosis fugax or retinal infarction and contralateral body transient ischaemic attack (TIA) or stroke. This review discusses the risk factors, clinical presentation, investigations, and treatment options for symptomatic and asymptomatic carotid atherosclerosis. All references to stenosis use consensus North American Symptomatic Carotid Endarterectomy Trial (NASCET) measurements.1 All recommendations reflect current UK guidelines, unless stated otherwise. Moderate to severe asymptomatic carotid atherosclerotic stenosis is found in 2-5% …