Choledocholithiasis is an urgent problem of modern hepatobiliary surgery and accounts for 60% of all obstructive jaundice. Stones of the common bile duct cause cholestasis and mechanical jaundice syndrome and in case of untimely diagnostics lead to the development of such severe complications as acute cholangitis and biliary sepsis. The criteria for determining the sequence, stages and volume of diagnostic measures with choledocholithiasis have not been determined by now. The purpose of the study. Optimization of the instrumental stage of the diagnostics of patients with choledocholithiasis. Materials and methods. 56 patients with choledocholithiasis were studied. The diagnostic program was expanded due to the instrumental stage using ultrasound, duodenopapiloscopy, endoscopic retrograde cholangiopancreatography and magnetic resonance tomography. The criterion for the patients selection was the syndrome of distal choledochal patency violation and the presence of stones in it according to echosonography and endoscopic cholangiopancreatography. Results and discussion. At sonography bilious hypertension was established in all 72 (100%) patients. Mechanical jaundice was present in 54 (96.4%) patients. Hepatic dysfunction with 84±9.6 mmol/l hyperbilirubinemia and an increase in AST and ALT levels to 1.2±0.9 mmol/l and 1.5±1.1 mmol/l, were verified respectively. At endoscopic retrograde cholangiopancreatography choledocholithiasis was found in 54 (96.4%) patients. Single stones were present in 18 (32.1%) and multiple – in 38 (67.9%) patients. In 52 (92.9%) cases, stones up to 1.5 cm in diameter were removed with a Dormia basket at one time or after mechanical lithotripsy. In 4 (7.1%) patients stones from 1.7 to 2.0 cm could not be removed endoscopically. Choledoch stenting was performed in 12 (21.4%) patients. One-stage transpapillary treatment was carried out in 38 (67.9%) patients, two and three stage treatment – in 14 (25%) cases, and «open» choledocholithotomy – in 4 (7.1%) cases. Conclusion. The program of choledocholithiasis diagnostics with the gradual use of clinical, laboratory, radiological and endoscopic data allows carrying out correct detailing of the cause, level, degree of common bile duct obstruction and the complicated course of the disease in 100% of cases