AbstractA gallstone is one of the most common digestive diseases, with incidence ranging from 10 to 20%. Acute cholecystitis is major morbidity following gallstones. Hence in our study by defining the pattern and type of gallstone, and establishing correlation with severity of acute cholecystitis we will open new windows for further investigations in the future helping in implementing the non-surgical interventions measures. A prospective study was done between July 2016 to March 2017 Patients diagnosed as acute calculus cholecystitis in department of general surgery, Adichunchanagiri institute of medical sciences were included in the study. Full history, clinical examination, ultrasound abdomen and laboratory blood investigations done, after which cholecystectomy was done and subjected to biochemical analysis. In our study, highest incidence was in fifth decade, with increase incidence in female, pain and fever wore most common symptom. Gallstone analysis showed mixed stone in 76% of cases and pigment stones in 16% of the cases as most common variety. Most of them were associated with grade one acute calculus cholecystitis. In our study we have found out that biochemical analysis of gallstones show there is no correlation between the type of gallstone and severity of acute calculus cholelithiasis by chi square test.