An increase in the thickness of the intima-media (IMT) of the carotid artery is associated with an increased risk of cardiovascular morbidity and mortality. Hypertension is one of the underlying mechanisms for the progression of carotid atherosclerosis. However, office blood pressure (BP) has been shown to have only a weak association with carotid IMT. Since self-measured home BP has less variation than office BP, home BP could be a better predictor of carotid atherosclerosis. To explore this hypothesis, we compared the relationships between carotid IMT and office BP or home BP in a community-dwelling population. One-hundred and one community residents, aged 50 years or older and not taking any medication, were enrolled in this study. Morning home BP was measured according to the guidelines of the Japanese Society of Hypertension. The results were recorded for 2 weeks and averaged. Carotid atherosclerosis was defined as IMT ≥0.80 mm, which corresponds to the first quartile. Home systolic BP showed a more significant association with carotid IMT (r =0.422, p <0.0001) than with office systolic BP (r =0.021, p =0.027). Logistic regression analysis for the presence of carotid atherosclerosis further showed that the relative risk of hypertension defined using home BP (≥135/85 mmHg) was 6.3 (95% confidence interval [CI]: 2.0 to 19.6), while that using office BP was 1.5 (95% CI: 0.5 to 4.2). These results suggest that home BP is a better predictor of the development of carotid atherosclerosis than office BP. (Hypertens Res 2004; 27: 633-639)