Homocysteine is considered to be an independent risk factor for atherosclerosis. Experimental animal models of hyperhomocysteinemia show aortic calcification, suggesting that this disorder is associated with aortic calcification in humans. A total of 28 patients with hyperlipidemia were enrolled into this study. The degree of aortic calcification at the level of the bifurcation and 1 cm proximal to the bifurcation was assessed by computed tomography of the aorta and the association between calcification of the aorta and the plasma level of homocysteine was then analyzed. The mean plasma homocysteine level in 28 patients was 8.7 microM. They were divided into 2 groups, high homocysteine level group (HHL; homocysteine level >8.7 microM) and low homocysteine level group (LHL; homocysteine level < = 8.7 microM). The degree of aortic calcification at the level of the bifurcation differed significantly between the two groups (19.1% vs. 10.5%; p < 0.01). We found that mild hyperhomocysteinemia was associated with aortic calcification, which suggests that interventions to reduce the plasma level of homocysteine may also reduce the severity of aortic calcification.