A 64-year-old man with primary esophageal lymphoma suffered from dysphagia. An upper gastrointestinal examination revealed a partly ulcerated submucosal tumor in the upper portion of the esophagus. Histopathological and immunohistological examination of endoscopic biopsy specimens showed diffuse large B-cell lymphoma of the immunoblastic type. Improvement of the dysphagia and esophageal findings were noted after chemotherapy and radiotherapy. A review of the literature indicated that primary esophageal lymphomas account for less than 1% of all gastrointestinal lymphomas, and less than 0.1% of all malignant lymphomas. Because of the rarity of primary esophageal lymphoma, its clinical and biological characteristics are not currently well known. It is important to accumulate information on, and to further investigate patients with, primary esophageal lymphoma.