We aimed to assess the association between retinal vascular caliber (RVC) scores and disease activity in rheumatoid arthritis (RA) patients.Materials and methods: Forty-seven RA patients, 32 systemic lupus erythematosus (SLE) patients, and 45 healthy people were enrolled. RA and SLE patients were subdivided into groups according to C-reactive protein (CRP) levels. RA patients were also grouped according to Disease Activity Score-28 (DAS-28). Fundus photography was performed for all patients. RVC was summarized as the central retinal artery and vein equivalents (CRAE and CRVE).Results: Mean CRVE for RA patients was 213.3 ± 17.8 µm compared with 209.2 ± 14.1 µm for SLE and 217.5 ± 26.2 µm for the control group (P = 0.17). RVC scores did not differ between the CRP-high and CRP-low groups. As the RA disease activity increased, the widening of CRVE became more prominent and statistically significant. When the DAS-28 > 5.1 (CRVE, 220.4 (211.8-246.5) µm) group and DAS-28 - 3.2 (CRVE, 214.4 (172.4-242.3) µm) group were compared, statistical significance was more pronounced (P = 0.03) than when comparing the DAS-28 > 3.2 and DAS-28 - 3.2 groups (P = 0.05). Conclusion: CRVE, which reflects systemic inflammation and possibly increased cardiovascular risk, was significantly increased in active RA patients. The association between retinal venular widening and disease activity, regardless of CRP, may be a sign that RA-related inflammation may have systemic vascular effects even with normal levels of CRP.