Carotid atheromatosis is the most frequent disease of the internal extracranial carotid artery. Although important advances have been made in the knowledge of its pathophysiology, relevant points remain unknown. The need for early diagnosis is conditioned by the high sociosanitary load of secondary cerebral ictus. Modification and treatment of the vascular risk factors are necessary for both primary and secondary prevention. The current diagnosis is fundamentally based on Doppler ultrasonography and imaging studies in B-mode in real time, angio MR, helicoidal CT and overall on digital angiography. The need to treat the neurologically asymptomatic stenoses, greater than 70% is still questioned by the slight benefit provided. To the contrary, the need for surgical treatment by endarterectomy in stenoses of greater than 70% is well established. Careful analysis of the ECST and NASCET series, however, leads to the suspicion that at the time of making surgical decisions, a series of predictive variables of the long term results should be considered to individualize the cases which may most benefit from this treatment. On the other hand, given the surgical morbimortality it seems reasonable to search for therapeutic alternatives to endarterectomy. One of these is percutaneous transluminal angioplasty, the results of which appear to provide a valid alternative, specially in the cases which can not undergo surgery.