Almost all East Asian strains and 60% of Western H. pylori strains are of cagA +. The infected patients develop a more pronounced inflammation with ulceration of stomach, and also are under a higher risk of development of cancer.Objective: to improve the informative value of dysplasia diagnosis by combining white light endoscopy with chromoscopy, supplemented by target brush biopsy with cytological examination.Methods and materials: for the period from 2016 to 2018, the study included 41 patients undergoing examination and treatment of chronic gastritis. The analyzed cases included 16 (39%) men and 25 (61%) women. The age of the patients ranged from 19 to 86 years. All patients underwent esophagogastroduodenoscopy, chromoendoscopy with 0.5% methylene blue, brush biopsy (scraping with a nylon brush). At least two brush preparations were obtained: body of the stomach, antrum, scraping was also made on the surface of erosions and areas of atypical structure of the epithelium. Brush preparations were sent for cytological examination. Results: esophagogastroduodenoscopy revealed erosions in 37 (90.2%) patients, in 6 cases (14.6%) among them spontaneous bleeding was determined. In 23 (56%) patients visual signs of atrophic gastritis were noted. Cylindrical epithelium of the intestinal type was revealed in 25 patients (61%) using methylene blue.The cytological examination of the brush preparation showed proliferation of the integumentary epithelium with signs of mild dysplasia in all cases, intestinal metaplasia was revealed in 27 patients (65.8%), H. Pylori was confirmed in 38 patients (92.6%).Conclusion: chromoscopy and brush biopsy are simple and affordable methods, and their integration into routine endoscopy increases the informative value of the study, namely, allows detection of precancerous lesions of mucosa.