Herein, we report a rare case of mediastinal ectopic parathyroid adenoma successfully treated by video-assisted thoracoscopic surgery (VATS). A 71-year-old female initially presented with general weakness and consciousness change. Biochemical examination revealed hypercalcemia and an elevated intact parathyroid hormone (i-PTH) level. 99mTc-sestamibi (MIBI) scintigraphy revealed an ectopic parathyroid gland in the anterior mediastinum. Chest computed tomography (CT) scan revealed a relatively well-defined soft tissue mass at the right anterior mediastinum, that was successfully treated with a videoassisted thoracoscopic surgerical approach. The postoperative course was uneventful, and her serum calcium and i-PTH levels returned to a normal range after operation. The pathologic report confirmed ectopic parathyroid adenoma. We report this case with a review of the literature.