Extranodal natural killer/T-cell lymphoma (ENKL) is an uncommon neoplasm, and it is a subtype of non-Hodgkin's lymphoma. It most commonly presents in the nasal cavity and nasopharynx. But only 10% of ENKL may present on the skin or the gastrointestinal tract and this has a poor prognosis. We report here on a case of CD56+ NK/T-cell lymphoma that limited to the esophagus. A 55-year-old male patient presented with epigastric soreness. Esophagogastroduodenoscopy (EGD) showed well demarcated, longitudinal ulcerative lesions with an irregular base and a discrete margin on the lower esophagus. We performed EGDs and endoscopic biopsies 2 times, but these were insufficient to make a diagnosis. The 3rd time, we finally took a big piece of tissue using endoscopic mucosal resection with a cap-fitted panendoscope (EMR-C). The biopsies showed surface ulceration and a heavy lymphoid infiltration and a positive pattern for CD3, CD56 and granzyme B. The pathologic diagnosis was NK/T-cell lymphoma. The patient was treated with concurrent chemoradiation followed by additional chemotherapy and he achieved a complete response.