Abstract BACKGROUND: Elevated free radical generation in inflamed joints and impaired antioxidant systems have been implicated in rheumatoid arthritis (RA). The present study was performed to evaluate dietary nutrient intake and plasma oxidant status in RA patients. METHODS: This case-control study comprised 75 RA patients and equal number of age- and gender-matched controls. Nutrient intake was estimated by using a semi-quantitative food frequency questionnaire. Blood samples were obtained from each group, and as an indicator of oxidant status, plasma concentrations of malondiadehyde (MDA) were measured. RESULTS: The mean calorie intake of RA patients was lower than that of the healthy controls. Energy-adjusted intake of fat, vitamin A and ß-carotene were significantly lower in patients than in control .Plasma MDA concentration was significantly higher in RA patients than in controls (4.9±1.8 vs 2.1±0.6 nmoles/ml respectively, P < 0.01). CONCLUSION: These results suggest proper antioxidant nutrient intake management may reduce free radical generation and improve antioxidant status in RA patients. Keywords: rheumatoid arthritis, antioxidant, malondialdehyde.