There are three compartments of regional lymph node to which metastases from thyroid cancers can occur: central, lateral, and mediastinal compartment. The mediastinal metastases from thyroid cancers are extremely rare, comparing the relatively common forms of metastases to central or lateral compartments. The importance of complete surgical lymph node dissection of central or lateral compartment for thyroid cancer has been well described, but mediastinal lymph node dissection has been sporadically reported. For mediastinal compartment metastases, operation techniques consist of sternal split, thoracoscopic surgery, or VATS (Video-assisted thoracoscopic surgery). Robotic surgery system was introduced recently with the objective of enhancing the dexterity and view during procedure that uses a videoscope. Many institutions report the experience with minimally invasive resection of mediastinal mass using robotic surgery system. We report that one case of robot-assisted mediastinal lymph node dissection for metastatic papillary thyroid cancer.