S. Kaur 1 , T. Kaur 1 1 Department of Biophysics, Panjab University, Chandigarh. India Background: A number of dietary factors have been involved in the pathogenesis of cholelithiasis. Cholesterol overfeeding is the primary means of inducing supersaturated bile and cholesterol gallstones in animal models.Aim of the study was to investigate the rate of epithelial cell death and proliferation in gallbladder during gallstones formation. Methods: Balb/c mice was divided into two groups control in this group animals were fed normal chow diet, High fat diet group in this group (2% cholesterol,0.5% sodium cholate, 5% butter fat and 15% coconut oil) mixed with chow diet was fed to the mice for 4 weeks. Cell apoptosis and proliferation was assayed in gallbladder epithelial cells. Histological analysis of gallbladder sections were done with hematoxylin and eosin staning. Results: Mice fed high fat diet had apoptotic as well as necrotic epithelial cells. Rate of proliferation was enhanced after 24 and 48 hrs in mice fed high fat diet group as compared to the control group. The histopathological section of control gallbladder has normal morphology whereas gallbladder wall thickness was markedly increased; epithelial cells appeared more elongated in mice fed high fat diet.