Lacunar (small deep) and small centrum ovale infarcts (LACIs and SCOIs, respectively) are both small subcortical infarcts with the same appearance on computed tomography (CT), but they are located in the different vascular territories of the deep and superficial perforating arteries, respectively. We compared the degree of carotid stenosis and risk factor profile in LACI and SCOI patients from the European Carotid Surgery Trial. The two patient groups were defined by the site and size of the symptomatic infarct on the pre-randomisation CT scan. The vascular risk factor profile appeared similar for the 129 LACI and 29 SCOI patients. However, SCOI patients had significantly higher degrees of carotid stenosis than the LACI patients (p < 0.025). Nineteen (66%, 95% confidence interval 49–83%) SCOI patients had symptomatic carotid large-vessel disease (stenosis ≧ 50%). Our findings suggest that SCOIs are associated with carotid large-vessel disease in the majority of patie