Background: Rheumatoid arthritis (RA) is a chronic, progressive, autoimmune disease affecting synovial joints with periods of flares which leads to joint erosion and bone destruction and consequent disability. Due to lack of diagnostic and prognostic markers to evaluate patients, several tests have emerged such as CTHRC1 protein. Methods: A case-control study was carried on 60 subjects ,30 healthy controls and 30 RA patients. Disease activity assessment was done for all patients using DAS28. Laboratory parameters as ESR, CRP,RF, anticcp . Serum CTHRC1 was measured in healthy individuals and RA patients using quantitative ELISA technique. Results: 30 RA patients (24 females and 6 males) with age mean of 37.3 ± 12.2 years and disease duration median of 5 years. We found that serum CTHRC1 was higher in RA patients than healthy controls.CTHRC1 was significantly correlated with DAS28 (p=0.02), tender joint number (p=0.004), swollen joint number (p=0.03) and dry mouth (p=0.03). No association was found between serum CTHRC1 and laboratory parameters. ROC curve analysis of serum CTHRC1 could significantly discriminate between active patients and in remission with a cut off value 10.3 ng/mL with sensitivity 65.4%, specificity 100%, PPV 100%, NPV 30.8% with area under the curve 83%. Conclusions: serum CTHRC1 is a favorable marker to evaluate RA patients. Significant association was found between serum CTHRC1 and disease activity which may serve as a valuable marker for RA patients monitoring.