The authors report 13 cases of intestinal bleeding; while serials endoscopic and radiological examinations had been negative, arteriography allowed intestinal angiodysplasia to be diagnosed, and detected 18 lesions (12 of the right colon, 6 of the small bowel), confirming the fundamental role of arteriography in the diagnosis the localization and extension of these lesions. The importance of accuracy is emphasized both in the performance and in the evaluation of angiographic findings, in order to avoid missing multiple localizations (colon and small bowel). The authors illustrate and evaluate the different angiographic findings. Among these, the collection of contrast medium into parietal vascular lacunae and the early and dense opacification of the draining veins appear to be the most specific and frequent findings of angiodysplasia. In their series of patients the authors have also observed how the dilatation of the feeding artery, up to the antimesenteric side (a sign which is hardly ever reported in literature), was often present in the cecal localizations but could never be observed in the small bowel. Finally the surgical results and follow-up are considered.