Helicobacter pylori (H. pylori) infection is an important etiological factor in the development of diseases of the stomach: chronic gastritis, peptic ulcer, stomach MALT-lymphoma and gastric cancer. Aim. Assessment of the frequency of detection of H. pylori infection in patients with morphological changes in the gastric mucosa according to a histological study. Materials and Methods. A retrospective study of medical records. We evaluated the results of histological studies of a biopsy samples of the gastric mucosa in patients tested for the presence of H. pylori infection using a rapid urease test. Results. The study included 221 results of histological evaluation of samples of the gastric mucosa of patients with chronic gastritis, gastric ulcer, polyps, and adenocarcinoma. Of 210 histological descriptions of morphologically altered gastric mucosa, 86.2% were associated with the presence of H. pylori. In 11 patients, morphological changes in the gastric mucosa were not detected, relatively more often 6.4 times (p <0.001) among H. pylori-negative individuals. Conclusions: H. pylori infection detected in 86.2% of patients with morphological changes in the gastric mucosa. Persons infected with H. pylori are 6.4 times less likely to have morphological unchanged gastric mucosa than persons who are free of infection, 2.7% and 17.1%, respectively (p <0.001).