Object study carbohydrate metabolism state in patient with GC during the surgical treatment period, and the detection of factors that influence these kind of disorders. The results of investigations of 270 patients with GC were analyzed. The rest of patients were males - 193 (71.48%). 239 patients underwent different surgical involvements. The state of carbohydrate metabolism was evaluated based on the study of the level of glucose in blood serum and urine at various stages of surgical treatment. The results of carbohydrate metabolism in 270 patients with gastric cancer in the perioperative period are analyzed. Factors that have an effect on the changes in glucose and insulin levels in the blood and its appearance in the urine before the specific treatment, as well as at various periods of staying patients in the surgical department, was the duration of the anamnesis, advanced stages of the oncological process, complicated clinical course of the underlying disease.. It was established that surgical intervention itself, its extension, and also postoperative period have a direct negative effect on the disorders in carbohydrate metabolism. In 65.3% of cases operations were accompanied by hyperglycemia, and in 25.9% of cases glucosuria was detected. The duration of a surgical operation for more than two hours lead to an almost twofold increase in the incidence of cases of hyperglycemia, and tripled increase in glucosuria. Intensive correction of blood glucose level along with enteral feeding led to a decrease in levels of hyperglycemia and glucosuria. Complicated postoperative period did not lead to an increase in the incidence of carbohydrate metabolism disorders, but had an effect on the longer retention of elevated levels of glucose in the blood and urine.