Background/aim: Rheumatoid arthritis (RA) is an autoimmune disease characterized by synovial inflammation. The study aimed to assess serum 14-3-3eta, anti-CarP, and anti-Sa in seronegative RA (SNRA) patients who were treatment-naïve as well as in healthy subjects. This is the first study in the literature to examine these autoantibodies together in SNRA patients. Materials and methods: Forty-five treatment-naïve SNRA patients and 45 healthy subjects were recruited. Drugs change the levels of autoantibodies; therefore, patients who took any medication had been excluded from our study. Anti-carbamylated protein, anti-Sa, and 14-3-3eta were measured by using three different ELISA kits.Results: Median serum concentration of healthy controls in 14-3-3eta was 0.02 (0.02?0.27) ng/mL. Median serum concentration of SNRA patients in 14-3-3eta was 1.00 (0.48?1.28) ng/mL. Data were analyzed with Mann?Whitney U tests; the P-value was