Because systemic lupus erythematosus (SLE) is associated with a high risk of atherosclerosis, a process that involves low-density lipoprotein (LDL) oxidation, we examined the hypothesis that raised fraction of LDL that is converted to oxidized (Ox) LDL expressed in OxLDL % of LDL (OxLDL %) is associated with the subclinical atherosclerosis in SLE. A cohort of 60 SLE patients with no previous history of cardiovascular disease had carotid artery ultrasound to identify plaques and to measure intima-media thickness (IMT). Forty females with rheumatoid arthritis (RA) were also enrolled in the study to serve as a control group. Plasma OxLDL concentrations were measured, and the OxLDL % of LDL were calculated. Traditional and SLE-related risk factors for atherosclerosis were evaluated. OxLDL % were significantly higher in SLE patients compared to patients with RA (p = 0.0311). OxLDL % were significantly higher in SLE patients with plaques than in those without plaques (p < 0.001). SLE patients in the highest IMT quartile have higher OxLDL % than patients in the lower three quartiles (p < 0.001). The odd ratio (OR) for the OxLDL % in patients with plaques was 6.143 (p < 0.001) when compared to patient without plaques, while OR for the OxLDL % was 8.34 (p < 0.001) in the patients with highest IMT quartile as compared to patients in the lower three quartiles after adjustment for confounding factors in logistic regression analysis. Our data provide evidence of an association between the circulating levels of OxLDL % of LDL with the risk for developing atherosclerosis in patients with SLE.