Objectives: The purpose of this study was to determine the influence of laparoscopic cholecystectomy on the diameter of the intrahepatic and extrahepatic bile ductsmeasured by magnetic resonance cholangiopancreatography. It was also to determine the possible correlation of intrahepatic and extrahepatic bile duct diameter and age, to investigate the possible association of diameter with biochemical parameters (bilirubin, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltransferase). Study Design: This prospective study was conducted at the Department of radiology, University Hospital „Sveti Duh“ Zagreb between March 2017 and July 2018. Participants and methods: The study group consisted of 48 patients (35 women) who underwent laparoscopic cholecystectomy due to gallstones. The control group corresponds to the examined group by age and sex, it consists of 48 people. The median age of the patients was 56 years.The intrahepatic and extrahepatic bile ducts were measured before and after cholecystectomy (3 months and 6 months). The diameter was measured at the anteroposterial and laterolateral direction, extrahepatic bile ducts were measured at eight measuring points, while intrahepatic bile ducts were measured at six measuring points. Results: The diameter of the common bile duct at the proximal part and the diameter of the common hepatic duct at the proximal part in the both direction were significantly wider 3 months after cholecystectomy (p<0.05) and 6 months after cholecystectomy (p<0.05). The right and left hepatic bile ducts were significantly wider 6 months after cholecystectomy when compared to the preoperative diameter in both direction (p<0.05). The segmental intrahepatic bile ducts in the both hepatic lobes were significantly wider 3 months after cholecystectomy (p<0.05) as well as 6 months after cholecystectomy when compared to the preoperative diameter (p<0.05). Conclusion: This study showed that postcholecystectomy dilatation occurs significantly only at certain points and not along the entire extrahepatic bile duct. We found significant dilatation after cholecystectomy of the bile duct in the proximal part and the common hepatic duct in the proximal part. We also found significant postcolecystectomy dilatation of the left and right hepatic ducts and segmental intrahepatic bile ducts.