Solitary extramedullary plasmacytomas are rare tumors, reported to occur most commonly in the upper respiratory passages, but which also are rarely seen in the middle and lower gastrointestinal system. This report documents the first primary plasmacytoma of the esophagus. A 67-year-old Caucasian man complained of dysphagia and weight loss. Preoperative diagnosis, based on functional inquiry, radiology, and biopsy, was undifferentiated carcinoma involving the lower third of esophagus. The patient was treated by esophagogastrectomy. The pathology specimen revealed the typical histology of plasmacytoma. The extramedullary nature of the tumor was established postoperatively on the basis of the following criteria: 1) Absence of Bence-Jones proteinurea; 2) normal serum electrophoresis; 3) normal bone marrow biopsy; and 4) absence of distant metastases on liver scan and bone survey.