OBJECTIVE: Many etiological factors such as glad bladder motility disorders, chemical component of bile and chemical content of bile have been accepted on gallstone formation; but anatomic variations of bile duct has been never discussed before. The aim of this study was to assess whether the anatomical measurements of cystic canal length, common bile duct length, choledoc length and the angle between the cystic duct and common bile duct junction (sistocholedochal angle: SCA) affects the gallstone formation. PATIENTS AND METHODS: MRI data of patients who had undergone magnetic resonance cholecysto pancreatography (MRCP) due to any reason, were collected retrospectively. A total of 126 patients was divided into two groups as without (group I; n=38) and with (group II; n=88) gallstone formation. The cystic canal, choledoc and common bile duct length and SCA measurements were obtained. RESULTS: There was no significant difference between two groups on the means of cystic canal, choledoc and common bile duct lengths (p > 0.05) but SCA measurements were significantly higher in group II compared with group I, statistically (p < 0.05); showing that as the SCA increases, the incidence of gallstone formation increases. CONCLUSIONS: Higher SCA values can be indictable on gallstone formation.