We recently encountered an unusual case of hilar cholangiocarcinoma in which a solitary recurrence in a mediastinal lymph node occurred two years after curative resection of the primary tumor. A 64-year old woman was admitted to our hospital with a complaint of right hypochondrial discomfort. After imaging studies demonstrated a hilar cholangiocarcinoma in the left hepatic duct, a curative resection of the tumor was performed, consisting of a left hepatic lobectomy along with caudate lobectomy, regional lymph node dissection, and resection of the extrahepatic bile duct. No nodal metastasis was observed histologically. Two years after surgery, the patient was found to have a nodule in the posterior mediastinum, which was thoracoscopically resected. No other swollen lymph nodes, local recurrence, or distant metastasis were noted. Histologically, the nodule proved to be a metastatic lymph node, and adjuvant chemoradiation therapy was initiated. The patient remained well for the four years following her first operation and had no evidence of disease recurrence 28 mo after her second operation. To our knowledge, this case is the first report of solitary recurrence in a mediastinal lymph node after curative resection of hilar cholangiocarcinoma. We recently encountered an unusual case of hilar cholangiocarcinoma in which a solitary recurrence in a mediastinal lymph node occurred two years after curative resection of the primary tumor. A 64-year old woman was admitted to our hospital with a complaint of right hypochondrial discomfort. After imaging studies demonstrated a hilar cholangiocarcinoma in the left hepatic duct, a curative resection of the tumor was performed, consisting of left hepatic lobectomy along with caudate lobectomy, regional lymph node dissection, and resection of the extrahepatic bile duct. No nodal metastasis was observed histologically. Two years after surgery, the patient was found to have a nodule in the posterior mediastinum, which was thoracoscopically resected. No other swollen lymph nodes, local recurrence, or distant metastasis were noted. Histologically, the nodule proved to be a metastatic lymph node, and adjuvant chemoradiation therapy was initiated. The patient remained well for the four years following her first operation and had no evidence of disease recurrence 28 mo after her second operation. To our knowledge, this case is the first report of solitary recurrence in a mediastinal lymph node after curative resection of hilar cholangiocarcinoma.