We present a patient with bilateral scalp necrosis caused by giant cell arteritis (temporal arteritis). A 67-year-old woman, who had been treated with 5 mg of oral prednisolone every other day for polymyalgia rheumatica, developed painful egg-sized regions of necrosis on both of her temples. Doppler pulsemetory revealed bilateral obstruction of the temporal arteries. Biopsy revealed ischemic necrosis of the skin and necrotic angiitis of the temporal arteries with giant cell infiltration. Bilateral stenosis of the internal carotid arteries and moderate retinal bleeding were revealed by angiography. Daily administration of prednisolone (20 mg/day) with intravenous and topical limaprost alphadex markedly improved her condition. The ulcers reepithelized without surgical treatment. There are few reports of bilateral scalp necrosis. Rapid and complete obstruction of the temporal artery may result in this condition. Simultaneous development of two ulcerative lesions in the ventro-parietal cranial regions is thought to correspond to systemic arterial involvement, including involvement of the internal carotid arteries.