The aim of this research is to determine the anti-peroxidative potential of Spirulina fusiformis in adjuvant-induced arthritis with respect to lipid peroxidation, and antioxidant status. Arthritis was induced by intradermal injection of Complete Freund's Adjuvant (0.1 ml) into the right hind paw of Swiss albino mice. Spirulina fusiformis (800mg/kg/day) and Indomethacin (3mg/kg/day) were orally administered for 8 days (from 11th to 18th day) after adjuvant injection. The lipid peroxide level, enzymic and non-enzymic-antioxidants status were measured in blood, liver and spleen of control and arthritic animals. In arthritic animals, the lipid peroxidation was found to be increased, whereas the decreased activities of antioxidant enzymes superoxide dismutase, catalase and glutathione peroxidase and non-enzymic antioxidant levels (Glutathione, vitamin C, and thiol groups), were observed. These observed alterations were significantly modulated to near normal levels by oral administration of Spirulina fusiformis (800mg/kg/day) in arthritic animals. In conclusion, the present study provides evidence that it may have a promising anti-arthritic role against rheumatoid arthritis. However, biochemical and metabolic analysis of the constituents of Spirulina fusiformis is on underway to investigate its mechanism of action.