We report a case of synchronous gastric adenocarcinoma and abdominal non-Hodgkin's lymphoma in a 56-year-old man. An explo-laparotomy was performed for the purpose of palliative resection of the stomach and to evaluate the nature of splenic and peri-pancreatic mass lesions. The pathologic stage of the gastric carcinoma was stage IB (T2N0M0) and the clinical stage of the diffuse large cell type lymphoma was IIA2S. Following surgery and chemotherapy, the patient is now in a disease-free state.