A synchronous presentation of an adenocarcinoma and a primary low grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) in the stomach is reported in a 73-year-old woman and a 55-year-old man. The diagnosis was based on microscopic examination of surgical specimens with immunohistochemistry. A possible etiology of the simultaneous presence of these two neoplasms in the stomach is discussed on the basis of our own material and review of the literature.