Roentgenologic findings in 6 of 7 cases of nonspecific granulomatous inflammation of the duodenum are presented. Among these are a smooth "string" sign, deviations in the size of the lumen which may be dilated or narrowed, areas of maximum stenosis, and variations in the mucosal appearance. The most common subjective and objective findings in these cases were epigastric pain, nausea, vomiting, fever, microcytic anemia, and weight loss of varying degree. No abdominal masses were palpable nor was there diarrhea, macrocytic anemia, or external fistulae. In one case an internal fistula was found at surgery with serous transudate around the duodenum; cultures and cell block were negative. In 2 cases there was roentgen evidence of duodenal ulcers. In only one case was an ulcer found at the time of surgery; without microscopic findings characteristic of peptic ulcer. Two patients exhibited involvement of the antrum of the stomach and the mid-jejunum. The incidence of regional enteritis involving the duodenum is thought to be more prevalent. The changes vary considerably from enteritis in the ileum and jejunum, because there is more early diagnosis in this area than in the distal small intestine. Severe ulcerative changes are seldom encountered. Spontaneous regression occurs but with incomplete resolution. Anatomical variations in the distribution of the regional lymphatics may be a factor in these differences.