Aim. To optimize the conservative treatment of patients with cholelithiasis. Methods. Conducted was a comprehensive in-depth examination and treatment of 87 patients with gallstone disease (cholelithiasis) at the stage of biliary sludge (in the initial physicochemical stage - before stone formation) with associated hypokinesia of the gallbladder. The diagnosis was verified by the means of ultrasound investigation, multifractional duodenal probing and the intensity of biliary sludge was determined by the content of cholesterol, bile acids (spectrophotometrically) and cholate-cholesterol coefficient in the bile. The content of microelements in the bile was estimated by the method of atomic emission spectroscopy with inductively coupled plasma. The spectrum of bile acids in the bile was determined by the method of matrix laser desorption ionization. The acid-producing function of the stomach was evaluated by the means of intragastric pH-metry. During endoscopy investigation a targeted biopsy of the mucous membrane of the anterior and posterior walls of the stomach was performed, followed by morphological examination of biopsy specimens. The patients were divided into two groups. Sulfate sodium-calcium mineral water «Uvinskaya» (Udmurtia) and ursodeoxycholic acid (Ursosan) was used in the treatment of patients of the observation group. In the comparison group monotherapy with ursodeoxycholic acid at a dose of 15 mg/kg body weight was conducted. Hydrotherapy in the observation group was conducted for 24 days, while medicinal treatment in both groups was continued for another 2 months. The control group consisted of 15 practically healthy individuals. Results. In the course of treatment a marked decrease in the pain in the right hypochondrium, the disappearance or reduction of dyspeptic complaints, loss of echo-positive particulates in the gall bladder and an increase in its contractility was noted in all patients of the observation group, at the same time the signs of inflammation also disappeared and the cholate-cholesterol coefficient increased. Registered was a favourable dynamics of the content of microelements in the bile. Conclusion. The combined use of the «Uvinskaya» mineral water and ursodeoxycholic acid for the treatment of cholelithiasis with biliary sludge promotes the most rapid elimination of clinical symptoms of the disease, improves the functional state of the gall bladder, reduces the lithogenic properties and normalizes the content of microelements in the bile.