We investigated the association of systolic and diastolic blood pressure and hypertension with two different manifestations of carotid atherosclerosis in a random population sample of 1165 Eastern Finnish men aged 42, 48, 54 or 60 years, examined in the Kuopio Ischaemic Heart Disease Risk Factor Study. Carotid atherosclerosis was assessed with high-resolution B-mode ultrasonography. Men with a casual sitting systolic blood pressure of 175 mmHg or more had a 3.17-fold (95% confidence interval 1.79-5.61) prevalence of intima-media thickening--adjusted for age, smoking, S-LDL-cholesterol, IHD history and diabetes--compared to men with lower systolic pressures. The relative prevalence of carotid plaques in men with raised systolic pressures. The relative prevalence of carotid plaques in men with raised systolic blood pressure was 2.61 (95% confidence interval 1.44-4.72) in relation to men with no lesions. Our findings suggest that systolic but not diastolic hypertension is associated with an increased prevalence of both early and advanced atherosclerotic lesions in carotid arteries.