Multiple lymphomatous polyposis (MLP) is a distinctive and particularly rare clinical type of malignant gastrointestinal lymphoma, which is classified as B-cell centrocytic non-Hodgkin's lymphoma. this rare entity has been recently reclassified as mantle cell lymphoma. We herein report three additional cases of MLP involving various segments of the gastrointestinal tract. MLP has an aggressive biologic behavior and a relatively poor prognosis and must be treated accordingly as a high-grade lymphoma with systemic chemotherapy.