An association has been reported between cardiovascular disease (CVD) and osteoporosis, perhaps attributable to the presence of common risk factors. To assess this possibility, we measured areal bone mineral density (BMD) and carotid artery intimal medial thickness (IMT), a measure of preclinical atherosclerosis, in 535 women and 335 men from the San Antonio Family Osteoporosis Study. Variance decomposition methods were used to determine whether cross-sectional measures of areal BMD (measured by dual-energy X-ray absorptiometry) of the total hip, spine, and forearm were correlated with IMT, serum lipids, and/or C-reactive protein (CRP), a marker of inflammation, after accounting for known environmental factors. We observed significant inverse correlations of IMT and BMD at all bone sites in women >60 years of age (P < 0.001) and modest positive correlations (not significant) of IMT on hip BMD (P < 0.1) in women <60 years of age. Similarly, we observed negative correlations between IMT and forearm BMD in men >60 years of age (P < 0.001) and positive correlations in men <60 years of age (P = 0.05). Variation in risk factors for CVD, including serum levels of low- and high-density lipoprotein cholesterol, low-density lipoprotein particle size, triglycerides, paraoxonase 1 activity, and CRP did not account for the relationship between BMD and IMT in either older or younger men or women. In summary, our results demonstrate that decreased BMD is correlated with increased IMT in older (but not younger) Mexican American men and women, independent of serum CVD risk factors.