OBJECTIVE To examine the relationship between patients gender, age and the development of different types of internal carotid artery plaque. METHODS Prospective open clinical study. METHODS 455 carotid duplex scans with a greater than 50% stenosis were analysed in terms of gender, age, degree of stenosis symptoms and plaque morphology. RESULTS There were 238 males (52.3%) and 217 females. Of 120 patients with type I plaque 86 were male (71.7%, chi 2 = 23.4, p = 0.000002). This high incidence of type I (haemorrhagic) plaque in men was accompanied by a higher degree of stenosis (chi 2 = 11.7 p = 0.0006) but was independent of the age of the patients and the presence of symptoms. CONCLUSIONS Although this study supports the view that men have more severe carotid artery disease, it does not to affect a younger age group. The higher degree of stenosis and its association with haemorrhagic plaque is not translated into an increase in symptoms in men.