A group of 306 patients with acute pulmonary hemorrhage were evaluated by means of bronchial arteriography and treated with transcatheter embolization. Specific causes for bleeding included lung abscess, chronic pneumonia, tuberculosis, lung cancer, and bronchiectasis. In 120 patients the hemoptysis was massive, with volumes exceeding 500 ml/day. The majority (n = 225) were treated during peak hemorrhage. Embolization was performed with one of three methods: particulate embolization with polyurethane or velour, obturation with the angiographic catheter combined with peripheral embolization by means of infused albumin macroaggregates, and regional infusion of sclerosing agents. Effective hemostasis was obtained initially in 278 patients (90.8%), including 87.5% of those treated during peak hemorrhage. In 26 of 28 cases without initial response, the pulmonary artery was the source of bleeding. Recurrent bleeding, within 1-4 days, requiring surgery was observed in 39 patients with initially successful hemostasis. Of 158 patients who were treated without surgery, subsequent episodes of hemoptysis occurred in 36. Combined methods of embolization may improve the efficacy of treatment of operable and inoperable patients with lung disease complicated by hemorrhage.