Introduction. Stomach cancer is a serious problem of modern medicine and is one of the most common malignant diseases in the world, being in fourth place among the causes of death from cancer. Most patients seek medical help in the late stages of the disease and, as a result, mortality during the first year after diagnosis is about 50 %.Description. A case of clinical observation of a patient with diagnosed ring-cell carcinoma of the stomach is presented. In the course of the description, key aspects that require attention in determining risk factors, examination tactics and management of a patient with suspected malignant gastric disease are highlighted.Conclusions. Detection of the disease in the early stages allows not only to significantly increase the patient’s chances of a complete cure, but also to carry out therapy using the most gentle methods. The differential diagnosis of peptic ulcer disease and infiltrative gastric cancer is particularly difficult. Comprehensive clinical, laboratory and instrumental examination of patients contributes to the early establishment of a correct diagnosis and, as a result, timely surgical treatment.