The purpose of the study is to improve the results of preoperative diagnosis and treatment of patients with Mirizzi syndrome. The work is based on the analysis of the case histories and clinical observations of 85 patients with chronic obstructive pulmonary disease with a complicated Mirizzi syndrome in the Surgery Clinic No. 2 ONMEDU from 2006 to 2018. There were 63 women (74%) and 22 men (26%). The age of patients ranged from 24 to 97 years. Among the patients studied elderly patients prevailed â 50 (69.3%) and senile age â 28 (3%). All patients 85 (100%) went to the hospital at different stages of development of calculous cholecystitis. In 53 (62%) patients, an acute attack of the disease was noted for the first time. Periodically repeated episodes were noted more often in patients in 32 (38%) patients. The clinical picture of the disease consisted of symptoms characteristic of acute and chronic cholecystitis with the development of mechanical jaundice. The most characteristic and frequently occurring symptoms were dull pain in the upper right quadrant of the abdomen â 58 (68.2%), jaundice and symptoms of cholangitis (chills, fever) â 42 (49.4%). In 41 (48.2%) patients type I CS was diagnosed, in â 29 (34.1%) type II, in 8 (9.4%) â type III, in â 7 (8.2%) patients with type IV CS. In type I, the choice method was laparoscopic cholecystectomy (LCE) in 36 (42.3%), LCE with drainage of choledochus in 10 (11.7%) patients. There were no iatrogenic bile duct lesions and no conversion in this group. The leading role in the treatment of patients with CS was given to open surgical interventions in 39 (45.8%). In type II, the main types of surgical intervention were: "open" cholecystectomy with plastic of the common bile duct on the Kehr's T-tube (in the presence of a defect of not more than 1/3 of the bile duct circumference) in 25 (29.4%); hepaticojejunostomy (in the presence of a defect of more than 1/3 of the circumference of the bile duct) in 14 (16.4%) patients. The main surgical operations with CS III-IV types do not differ in principle from the above operations. So, the use of highly sensitive diagnostic methods and a combination of endoscopic and surgical treatment can significantly improve the results of treatment of patients with Mirizzi syndrome.