Rheumatoid arthritis (RA) is characterized by chronic inflammation, joint destruction and an increased risk for cardiovascular morbidity. Dietary intakes of omega-3 and omega-6 polyunsaturated fatty acids affects inflammation and cardiovascular risk.To assess the influence of omega 3 and omega 6 fatty acids in patients with rheumatoid arthritis through inflammatory parameters and through oxidative stress.60 patients with RA is divided into the first group (20 patients), to which 5 of gel capsules Omega 3  for 3 months, the second group (20 patients) who have taken after 3 of gel capsules Omega 3  and two gel capsules oil evening primrose oil for 3 months, and the third, control group (20 patients) who were taking no supplements. Analysis of biochemical parameters of endothelial function and parameters associated with acute and chronic effects of oxidative stress: (О2∙-, H2O2,NО∙, TBARS, SOD, CAT, GSH) was performed in the Laboratory of Cardiovascular Physiology at the Faculty of Medicine in Kragujevac. Measurements were performed on the AnalyticJenaSpecordS 600 spectrophotometer.Prooxidant and antioxidant actions are parameters in the groups of patients with RA who received supplementation with omega-3 and omega-6 fatty acids showed a decrease in oxidative stress and the increase in activity of the antioxidant protection system. Supplementation of omega 3 and omega 6 fatty acids in patients with RA affects the reduction in disease activity..In subjects suffered from  rheumatoid arthritis who took concentrated fish oil supplements with omega-3 fatty acids as a dietary supplement, there was an increase in the level of antioxidant protection parameters and a decrease in the level of prooxidants, which was confirmed by group analysis.It has been observed that in some people the clinical effect is absent. Genetic variations affect the way the body responds to certain nutrients and food components, and materials that can break down and properly utilized. That's why some individuals have it and some don't, which is the subject of further research into genetic variants in the genes that encode enzymes for the metabolism of omega 3 and omega 6 fatty acids.