Abstract: Introduction: Oxygen free radicals that are generated mainly through the phagocytic activity of the polymorphonuclear leucocytea have been implicated as mediators of tissue damage in patients with rheumatoid arthritis (RA). Accordingly low levels of antioxidants, which increase free radical activity, are clearly associated with an increased risk of RA. Methods: Of 24 patients who entered the study 14 patients were excluded because they failed regular follow up. The analysis was done on 10 patients who fulfilled the ACR criteria for RA. They were all on chloroquine and methotrexate plus low dose prednisolon. The patients were evaluated at zero, 6, and 12 months. The clinical (general symptom, morning stiffness, index of swelling, pain and limitation of joints) and laboratory (ESR, RF, CRP, CBC, endogenous antioxidant such as lipid profile, uric acid, bilirubin, plasma ceruloplasmin) finding and the status of antioxidant capacity of plasma by FRAP were evaluated at each control. Results: The mean age of onset of RA in our patients was 36.8+ 8.20. The mean age at the beginning of combination therapy was 41.8+ 8.94. Reduction of morning stiffness and improvement of general symptoms were statically significant after 6 months (p< 0.021). Index of swollen, painful and limited joints were decrease after 12 months of the initiation of combined therapy (p<0.002). The effect of combined therapy on laboratory tests was statistically significant only for ESR (p<0.05). Combined treatment had not any results on endogenous antioxidant except for high-density lipoprotein (HDL). The increase of HDL was statistically significant after 6 and 12 months. The level of cereloplasmin did not change during the treatment. Antioxidant status of plasma increased after the initiation of combination therapy but it was not statistically significant. Its maximum level was 682.6 mmol/lit after 6 months. Conclusion: Although combination therapy had good results on clinical symptoms, it had no effect on the status of antioxidant capacity of plasma in RA.