A case of schwannoma originating in the right intrathoracic vagus nerve was reported. A 72-yearold woman had an abnormal shadow in the right upper mediastinum on a chest roentgenogram. A CT scan and MRI revealed a tumor in the upper mediastinum compressing the trachea, right carotid artery and right subclavian artery. An incisional biopsyof the mass in the right neck was revealed to be benign schwannoma. The mass was 55 ×42×29mm in size and originated from the right vagusnerve at the proximal level and extended to the branch of the recur-rent laryngeal nerve. There was no evidence of invasion of the mass into the surrounding organsand tissues were evident. Subcapsular ex tirpation was done preserving the nerve fibers. However, postoperative hoarseness due to dysfunction of the recurrent laryngeal nerve occurred. Mediastinal schwannoma originating in the vagus nerve is notso common ; 29 cases have been reported in Japanese literature.