Transcatheter arterial embolization has recently emerged as a highly effective percutaneous technique for controlling acute and chronic genital bleeding in a wide variety of obstetric and gynecologic disorders. Benefits for the patient and health care system have included low complication rates, avoidance of surgical risks, fertility preservation, and shorter hospitalizations. In this article the current indications for pelvic embolotherapy, types of embolotherapy, technical considerations, immediate success rates, causes of failure, complications, and outcome expectations are discussed. Our comprehensive literature review and clinical experience suggest that embolization should be used before surgical treatment of nonmalignant pelvic bleeding in many clinical settings, including postpartum, postcesarean, and postoperative bleeding. It is our strong belief that this form of therapy is underused, and the primary purpose of this article is to emphasize its developing role as a highly effective, relatively noninvasive method of treating genital bleeding. (Am J Obstet Gynecol 1997;176:938-48.)