AbstractThis paper reviews small intestinal lymphoma. Although a major emphasis is placed on primary small intestinal lymphoma of the “Western” type, the important topic of lymphoma in celiac disease is discussed. Our own recent experience of 7 patients with lymphoma in celiac disease is presented. The lymphoma of immunoproliferative small intestinal disease (“Mediterranean” lymphoma) and the associated α‐chain disease are also reviewed, with emphasis on the differences from the “Western” type of primary small intestinal lymphoma.