Abstract. Cholangiocarcinoma (CCA) or bile duct cancer is a rare cancer type in developed countries, while its prevalence is increased in southeast Asia, affecting ~33.4 men and ~12.3 women per 100,000 individuals. CCA is one of the most lethal types of cancer. Neo-adjuvant and adjuvant therapies have been shown to have limited efficacy in improving the overall prognosis of patients. Radiotherapy has been reported to prolong the survival times of patients with certain characteristics. The present study retrospectively evaluated the medical records and follow-up data from 27 CCA patients who received radiotherapy at Chulabhorn Hospital (Bangkok, Thailand) between 2008 and 2014. A total of 14 patients underwent surgery followed by adjuvant chemoradiotherapy. Of the 27 CCA patients, 14 had intrahepatic CCA, 2 had extrahepatic CCA and 11 had hilar CCA. The 2-year survival rate was 40.7%. Tumor resectability, clinical symptoms and the Eastern Cooperative Oncology Group performance status score were found to be indicative of patient prognosis. In addition, the planning target volume and biologically effective radiotherapy dose were of prognostic value; however, initial treatment response was ambiguous in predicting survival time. The findings of the present study suggested that the currently used radiotherapy protocols for CCA may require modification to improve their efficacy.