Although most cases of acute gastrointestinal (GI) hemorrhage either spontaneously resolve or respond to medical management and/or endoscopic treatment, there remain a significant number of patients who require emergency evaluation and treatment by the interventional radiologist. Any angiographic evaluation should begin with selective catheterization of the artery supplying the most likely site of bleeding, as determined by the available clinical, endoscopic, and imaging data. If a source of hemorrhage is identified, superselective catheterization followed by transcatheter embolization with microcoils is the most effective means of successfully controlling hemorrhage while minimizing potential complications. This is now well-recognized as a viable and safe alternative to emergency surgery. In selected situations transcatheter intra-arterial infusion of vasopressin may also be useful in controlling acute GI bleeding. One must be aware of the various side effects and potential complications associated with this treatment, however, and recognize the high rebleeding rate. In this article, we review the current role of angiography, transcatheter arterial embolization, and infusion therapy in the evaluation and management of GI hemorrhage.