The article deals with the results of treatment of 180 patients with the Mallory-Weiss syndrome. Morphological studies of the gastric wall was conducted in 16 patients who underwent operation. It was established that developmental anomalies, chronic gastritis, and pathological changes of the vessels of the lamina muscularis mucosae impairing its mobility and strength may be the morphological substrate which precedes the development of the Mallory-Weiss syndrome.