Aim: The aim of the study was to assess mucosal microflora of the stomach of patients with RA according to the degree of disease activity. Materials and Methods: We analyzed 159 people aged 19 to 83 years. Among the patients, mostly women were 128 and men were 31. The ratio of women to men - 4.13:1. The mean of age is 55+0.86 years of all patients. RA was diagnosed in all cases by using the criteria of the American College of Rheumatology. In this study we used for determining RA that routine clinical and radiographic examination, microbiological examination of feces and urine, endoscopy (used machine company "Olympus") of stomach and duodenum with biopsy of the mucosa; it was carried out a microbiological study of the stomach and gastric juice biopsies of mucosa. Results: In the study of biopsy results showed that RA patients’ microflora of stomach insulated Peptostreptococci – 78.5% patients; Streptococci, Staphylococci and Bacillus – 28.5% patients; Escherichia coli and yeast-like fungi of the genus Candida – 21.4%; Clebsiella, Pseudomonas, Enterococci – 8.3% patients in number of cultures from 103 to 3.6x107lg CFU/ml and the combination of microorganisms are from 1 to 7. Escherichia coli were inoculated in an amount of 4.1x107lg CFU/ml; Streptococci – 3.6x107lg CFU/ml; Clebsiella and Pseudomonades – 106lg CFU/ml; Peptostreptococci – 7.6x103lg CFU/ml; staphylococci – 6x103lg CFU/ml; Candida – 1.7x103lg CFU/ml; Enterococci – 103lg CFU/ml. Conclusion: In patients with RA are marked dysbiotic changes in the stomach. The severity of dysbiosis is directly dependent on the activity of joint pathology.