Background/Aim: Pancreatobiliary cancer is a disease associated with a dismal prognosis and limited treatment options. The aim of the present study was to clarify the usefulness of circulating galectin-3 in pancreatobiliary cancer. Patients and Methods: We examined serum galectin3 concentrations in 45 patients with pancreatobiliary cancer. Receiver operating characteristic curves were utilized to evaluate the accuracy of circulating galectin-3 to discriminate pancreatobiliary cancer patients from controls and predict the prognostic outcomes. Results: Circulating galectin-3 had diagnostic value at the cut-off level of 6.2 ng/ml, and the patients' overall survival was predictable at the cut-off level of 10.3 ng/ml. Furthermore, circulating galectin-3 >= 10.3 ng/ml was an independent prognostic marker in pancreatobiliary cancer. Regarding biliary cancer, higher galectin-3 was associated with malnutrition. On the other hand, regarding pancreatic cancer, higher galectin-3 levels were associated with higher inflammatory parameters. Conclusion: Galectin-3 can be a useful biomarker in patients with pancreatobiliary cancer.