We report a case of a 74-year-old woman with an esophageal gastrointestinal stromal tumor (GIST). Endoscopic examination suggested a submucosal tumor in the middle-lower thoracic esophagus. Computed tomography showed a solid mass 95 × 56 × 44 mm in size, suggesting an esophageal mesenchymal tumor. Endoscopic ultrasonography-guided fi ne-needle aspiration biopsy was positive for c-kit and CD34, and negative for both S-100 and desmin, on immunohistochemical examination, confi rming this to be a GIST. The patient underwent transthoracic esophagectomy with esophageal reconstruction using a gastric tube through the subcutaneous route. The tumor was completely resected, and there was no lymph node metastasis. The pathological examination confi rmed the tumor to be at high risk for recurrence because of its size and the presence of necrosis. We are carefully following the patient conservatively with no adjuvant chemotherapy such as imatinib mesylate.