Aim: The biliary fistula development after liver hydatid cyst surgery is a common complication. The aim of this study is to examine the factors affecting the development of postoperative biliary fistula in patients operated for liver hydatid disease. Methods: The study was retrospectively performed in patients treated surgically for liver hydatid cyst between 1999 and 2010. The data of 53 patients operated for hydatid csyt were reviewed with hospital records. Patients were divided into two groups as biliary fistulas with (Group A) and without biliary fistula (Group B). The demographic data (age, sex), cyst diameter, cyst localization, laboratory tests and length of hospital stay were recorded. These parameters were compared with the groups. Results: The groups were similar in terms of age and sex (p = 0.790 and p=1.0, respectively). In group A, the mean cyst diameter was significantly higher than group B (p=0.001). The mean duration of hospitalization was longer in group A than group B (p=0.001). There was no difference between the groups considering cyst localization, AST, ALT, total bilirubin and direct bilirubin (p>0.05 for all). Conclusion: Preoperative cyst diameter may be a valuable parameter for predicting biliary fistula preoperatively. However, larger prospective studies are needed on this subject.