Glucose metabolism is evaluated before and after the operation in 51 patients (41--men, 10--women), operated on account of the complicated chronic pancreatitis. The distal pancreatic resection (50% of the gland) was performed in all cases. The middle age of the patients is 41.2+/-7.9. Body mass index (BMI) was 23.7+/-3.4 kg/m2. After distal pancreatic resection 33.33% of patients with chronic pancreatitis didn't have glucose metabolism disturbances. In 27.45% of patients diabetes mellitus was diagnosed for the first time after the operation. At the same time, in 5.8% of cases the worsening from the light to the moderate form of diabetes mellitus was observed. As far as blood glucose level (glycemic control) doesn't have any prognostic value in predicting diabetes mellitus in early postoperative period, it is necessary to recommend regular supervision by the endocrinologist to the patient after discharge. All patients with chronic pancreatitis should be carefully investigated so as to detect glycaemic disorders. It is recommended to determine fasting blood glucose level, glycemia throughout the day, glycated hemoglobin, 24 hours' glucosuria. It is also essential to perform an oral glucose tolerance test (OGTT).