The role of the surface characteristics of carotid artery lesions in the long-term prognosis of cerebrovascular disease has not been established. 184 patients who presented with symptoms of hemispheric TIA or retinal ischemia, and had ipsilateral carotid artery atheromatous disease, were clinically followed 5-8 years (mean 6.3 years) after initial presentation. Based on the findings of the initial duplex ultrasound examination, a comparison was made between those patients who suffered a vascular event in the follow-up period and those who remained alive and without subsequent vascular symptoms. The only significant difference found between the groups was the distribution of the lesion surface characteristics (p < 0.01). The degree of stenosis caused by the lesion or the size of the low-echo pool within the lesion were not found to be significantly associated with subsequent clinical events. The results of this study emphasise the importance of the ultrasound evaluation of the carotid lesion surface characteristics, and their inclusion in the criteria for decisions on patient treatment.