The carotid artery is an important vessel that supplies blood to vital organs including the brain. Therefore rupture of the carotid artery may induce serious neurologic deficits and high has a mortality rate. Rupture of this artery may be induced by a number of pathologic processes. The most common causes are malignant tumors, but effects of radiotherapy, infection, exposure, and trauma (including surgical trauma) may on occasion involve the carotid artery. Whether a surgeon should resect the carotid artery or not is the most important question when a mass involves the carotid artery to such an extent that the mass cannot be completely removed without removing a portion of the carotid artery. Authors experienced 13 cases of carotid ruptures and five cases of elective ligations that had previously received radiotherapy and surgery, or both. The following results were obtained : 1) Histologically, 15 cases were squamous cell carcinomas, two were anaplastic carcinomas, and one was adenocarcinoma arising from larynx. 2) By staging, 12 cases were stage IV and six were stage III. 3) Emergency ligations were six cases, of which two patients died within 72 hours due to anoxic damage to brain, one case had hemiplegia but was alive, and three patients were survived without any neurologic deficit or further rupture. 4) Two cases of ruptures were alive with primary repair of carotid artery. But five cases died by hypovolemic shock before any managements were given. 5) More than two prediposing factors were present in all cases. 6) The sites of rupture were eight common carotid arteries, three carotid bodies, and two internal carotid arteries. 7) Five cases that received elective ligation had no nerologic deficit, and mean follow up was 4.7±4.3 months.