Systemic lupus erythematosus (SLE) is a chronic autoimmune disease of unknown etiology. A major cause of morbidity and mortality in SLE is accelerated atherosclerosis. Endothelial-specific molecule 1 (endocan) is a potential predictor of vascular events and is expressed in response to inflammatory cytokines in endothelial cells. We investigated the relationship between endocan and carotid intima-media thickness (cIMT) as a marker of early atherosclerosis. We included 44 women with SLE and 44 healthy women as controls. Disease severity of SLE was evaluated using the SLE Disease Activity Index. Endocan, C-reactive protein, erythrocyte sedimentation rate (ESR), and lipid panel were measured. The cIMT was 0.70 (range: 0.45-1.20) mm in patients with SLE and 0.40 (0.25-0.60) mm in controls (P < .001). Endocan value was 1.6 +/- 0.9 ng/mL in controls and 2.2 +/- 1.0 ng/mL in patients with SLE (P = .014). Endocan levels were positively correlated with cIMT (r = .469, P < .001), body mass index (r = .373, P = .013), and ESR (r = .393, P = .008). Endocan level may be associated with subclinical atherosclerosis in SLE. Consequently, endocan levels may be a promising clinical tool for patients with SLE as a guide for preventive strategy.