PRIMARY malignant disease of the small bowel is comparatively rare. As Morison1 has stated, "For the area exposed, the small intestine enjoys as great an immunity from new growth as any part of the body." During the past few years, this condition has aroused increasing interest. The chief difficulty has been early diagnosis, but with the better technics now available for the roentgenologic investigation of the small intestine, its presence can be demonstrated sufficiently early to offer hope of successful surgical intervention. Awareness of the possibility remains, however, the prime necessity for its recognition and offers a challenge for early diagnosis. The present communication is a report of 15 cases encountered at City Hospital, Welfare Island, and 2 cases from other sources. They are separated into three groups, i.e., cases of carcinoma, cases of carcinoid or argentaffinoma and cases of lymphosarcoma, because of the differences in pathologic and clinical