A 69 -year-old female with advanced gallbladder cancer underwent cholecystectomy, S4a/S5 segmentectomy of the liver, and resection of the extra-hepatic bile duct in October 2005. Adjuvant chemotherapy consisted of gemcitabine (GEM) and tegafururacil (UFT) administered consecutively. Four years after surgery, computed tomography revealed a single enlarged lymph node in the mediastinum, along with ¹⁸F-fluorodeoxyglucose accumulation and increased carcinoembryonic antigen (CEA) levels. Therefore, the mediastinal lymph node was considered to be a metastasis and GEM was readministered. Although the patient was treated with GEM for 1 year, the accumulation of 18F-fluorodeoxyglucose in the lymph node remained elevated. No other distant metastases were detected. Abronchoscopic biopsy histologically confirmed mucinous adenocarcinoma in the lymph node. Thus, the mediastinal lymph node was resected. Post-surgery, there was no evidence of recurrence during the 30-month follow up period without chemotherapy. Herein, we report a successful case of surgical treatment for solitary mediastinal lymph node metastasis of gallbladder cancer and review the relevant literature.