A 55-year-old man with a past medical history of gastric ulcer and diabetes mellitus was brought to our hospital by ambulance for acute abdomen. Enhanced abdominal computed tomography showed thickened small intestinal wall with free air and ascites. Under the diagnosis of perforative peritonitis, an emergency operation was performed. Upon laparotomy, a intestinal tumor with a perforation in the jejunum was identified, for which a part of the jejunum encompaning the perforated tumor. Immunohistochemically examination demonstrated that the tumor cells were positive for CD3, CD4, CD8 and CD56 and negative for CD5 and CD20. Therefore, the jejunum tumor was diagnosed as type Ⅱ Enteropathy-Associated T-cell lymphoma. Herein, we report our case, together with a review of the literature.