We aimed to investigate whether there is a relationship between blood fibrinogen levels during hospitalization of patients hospitalized for conservative treatment due to acute cholecystitis (AC) in our clinic. Patients underwent surgery and were discharged with medical treatment. The files of 118 patients who were hospitalized due to the diagnosis of AC and planned for conservative medical treatment in our clinic between January 2018 and February 2020 were recorded, prospectively. The patients were divided into two groups as those who responded to conservative treatment (Group 1), and those who were operated urgently despite conservative treatment (Group 2). Increase in gallbladder wall thickness, presence of pericholecystic fluid and hydrops sac on ultrasound and computed tomography (CT) were considered significant for the diagnosis of acute cholecystitis. Blood fibrinogen levels were measured in all patients during hospitalization. The mean age of 118 patients included in the study was 58.32 (19-96) years. There were 77 patients in Group 1 and 41 patients in Group 2. Serum fibrinogen level was found to be 298.34±111.7 mg/dl in Group 1 and 637±124.5 mg/dl in Group 2, and a statistically significant difference was found (p<0.001). When the cut-off value for the fibrinogen level was taken as 564.50 mg/dl, the sensitivity and specificity of the test were found to be 75.6% and 61%, respectively in showing surgical treatment. As a result of our study, we concluded that when the data obtained are evaluated, it should be kept in mind that despite medical treatment, there is an urgent need for an operation in patients with acute cholecystitis, and in patients with high plasma fibrinogen level (cut-off) at first admission.