A 74-year-old woman visited our hospital with complaint of loss of consciousness, and a mediastinal tumor was discovered by chance in computed tomography (CT). A chest CT showed a lobulated tumor with a maximum diameter of 8 cm, which was located at upper mediastinum extending to cervix and was compressing the esophagus. Magnetic resonance imaging (MRI) showed uniformity and clear boundary tumor. A hypermetabolic appearance (maximum standardized uptake value, 15.0) was noted on positron emission tomography (PET). Based on these data, a gastrointestinal stromal tumor was suspected. The patient was placed in the left lateral position and underwent anterolateral thoracotomy via the sixth right intercostal space. At the same time, the skin incision was added in the right side of the cervix. The tumor was enucleated at the thoracic cavity while being pushed from the cervical incision. The muscular layer of esophagus was repaired with sutures. The operation time was 245 min, and the blood loss was 551 g. The specimen showed a well-demarcated, elastic hard, and lobulated appearance and was measured 80 × 42 mm. The cut surface was almost uniformly pale yellow. Hematoxylin and eosin staining revealed spindle-shaped cells configuring plexiform proliferation. Immunohistochemical examination revealed S-100 protein positivity and c-kit, α-smooth muscle actin, desmin, and CD34 negativity, establishing the diagnosis of esophageal schwannoma. The MIB-1 labeling index was < 10%. Her postoperative course was uneventful, and no recurrences have seen for 5 years after surgery.