Background/aim: Human endothelial cell-specific molecule-1 (endocan) is a marker of vascular endothelial dysfunction that may be used in the evaluation of inflammatory-associated atherosclerotic lesions. Endocan may be a marker for the evaluation of atherosclerosis and disease activity in rheumatoid arthritis (RA) patients.Materials and methods: We included 39 RA patients assessed according to the American College of Rheumatology/European League Against Rheumatology 2010 diagnostic criteria and recruited 30 age- and sex-matching healthy subjects for the control group.Results: Endocan values were 14.11 ± 3.27 for the RA patients and 12.10 ± 2.92 for the controls. The endocan values of the patients were significantly higher than those of the control group (P = 0.009). In the correlation analysis, endocan showed a significantly positive correlation with disease activity score-28 (r = 0.386, P = 0.029) and carotid intima-media thickness (cIMT) (r = 0.419, P = 0.008). Linear regression analysis revealed that there was an independent relationship between endocan and cIMT (P = 0.029).Conclusion: Endocan can be a marker for early atherosclerosis and disease activity in RA patients.