Five new cases of malignant hemangioendothelioma of the thyroid are reported. This rare malignant tumor is described predominantly in regions with endemic goiter such as the Alpine zone. The estimated incidence of the disease is between 0.15 and 0.25 per 100,000 inhabitants per year for Western Austria. Two of the five patients were heavily exposed to vinyl chloride occupationally for 9 and 30 years respectively. Surgically, a R-0 resection was performed in two patients, R-1 in two, and R-2 in one patient. Postoperative radiotherapy was given in four cases. The tumor doses were between 58 and 65 Gy. Three patients received the sensitizer razoxane in addition. Local tumor control was achieved in 4 of 5 patients. The survival times of the 5 patients were 78, 68+, 38+, 7.5 and 3 months. Two patients are still alive after 68 and 38 months. This small series may indicate that the outcome of the disease may not be uniformly deleterious and the resistance to radiotherapy reported in the literature [3, 10] is debatable.