A histopathologic study including iramunohistochemical stains was made in 30 patients who were presented with gastrointestinal lymphoma. The occurrence was 13 in the stomach, 8 in the ileocecum, 7 in the small intestine and 2 in the colon. The disease more frequently affected males than females and the average ages were 53 years in the patients of gastric lymphoma and 44 years in the patients of intestinal lymphoma. Gastric lymphomas were usually presented with a single lesion, and the antrum and/or body were the most common sites. But intestinal lymphomas were presented with a single or multiple lesion, and the ileocecum was the most common site. The most common gross type of gastrointestinal lymphomas was the ulceroinfiltrating type and most are of the diffuse large noncleaved cell type of B-cell lymphoma, histologically. There were 2 cases of T-cell lymphoma presented in the intestine as the superficially ulcerative gross pattern and diffuse immunoblastic cell type. The distinct MALToma was seen in only one case of stomach but the feature was partially remained in each two cases of stomach and intestine. Their coexistent findings may suggest that diffuse large of immunoblastic component arises through blastic transformation of the low-grade M ALToma component.