We report a case of spontaneous submucosal dissection of the esophagus of a 58-year-old patient. In September 2005, he complained of chest pain followed by vomiting. Endoscopy showed an ulcerative lesion in the entire circumference of the middle esophagus. No malignant cells were observed in biopsy specimen. The patient received therapy with hyperalimentation, a proton pump inhibitor, and Alloid G. The lesion healed under conservative treatment with a good clinical course and without the development of stenosis. One year later, we performed 24-h pH monitoring and esophageal manometry to clarify the pathogenesis of submucosal dissection in this patient. There was no gastroesophageal reflux, but the manometry test revealed decreased amplitude in the portion of the esophageal lesion that was considered to be caused by fibrosis resulting from inflammation. Two years later, the patient had no complaint of dysphagia. Further follow-up is needed for such a case.