Selective angiography is the technic which provides a higher accuracy in diagnosing an acute mesenteric arterial insufficiency. If carried out at an early stage it surpasses any other technic. It permits not only obtaining topographic data to locate the occlusion but also the detection of aspects of the collateral circulation in the loops of the bowel, thus enabling us to determine the therapeutic procedure to follow. We have done selective angiography of the superior mesenteric artery in nine patients in all of whom we identified the embolic disease. In five of these patients the embolus was in the main trunk and in four it was in the distal branches. The mortality rate varied depending on the site of the embolus and the time elapsed in the process. In three of the patients with distal localization and in one with trunk localization and sufficient arterial permeation, a conservative therapy was used with good results in all of them.