Background: Carotid artery stenosis is not thought to be a major cause of stroke in sub-Saharan Africa, though data are limited. The aim of this study was to use Duplex ultrasonography to establish the prevalence of significant carotid artery stenosis in an incident stroke population in Tanzania. Methods: Duplex ultrasound scan was carried out on consecutive cases of stroke, in the latter part of a stroke incidence study, who survived long enough to undergo investigation. As part of the wider incidence study, demographic data, social history, medical history, levels of current disability and findings from computer tomography scan and electrocardiogram were recorded. Results: 132 incident stroke cases were identified over the whole study period, of whom 56 (42.4%) underwent Duplex ultrasound. Only 1 case (female, aged 56 years) had evidence of right internal carotid artery stenosis, with a mild degree of stenosis of around 50%. There was no evidence of stenosis of either common carotid artery or of the left internal carotid artery in any cases. Conclusions: Carotid artery stenosis was rare in our cohort and does not appear to be a significant cause of stroke in our incident cohort.