From 1987 to 1989, 7 patients were diagnosed as having a primary lymphoma of the small bowel. The patients, 5 men and 2 women aged 14-66 years (average: 45), were studied by means of small bowel enema and CT. Using small bowel enema, our findings were: masses related to a loop, stenosis, mucosal patterns with thick, irregular, and nodular folds, and bowel walls thickening. In nearly all cases CT showed not only small bowel lesions but also mesenteric lymphadenopathy. Five of seven patients had lymphomas, 1 had IP-SID lymphoma (immunoproliferative small intestinal disease related lymphoma), and 1 had IPSID associated with a late prelymphomatous stage. The diagnosis of IPSID is very important in patients with malabsorption syndrome, which may or may not be related to alpha heavy chain disease, because IPSID may evolve into lymphoma but its prelymphomatous stage can be treated and cured. We have therefore reported the different features seen with enteroclysis and CT, comparing the results obtained in the various forms of lymphoma of the small bowel. The importance is stressed of an accurate diagnosis of IPSID forms, however uncommon in our Country.