The authors report a case of Horton's arteritis in a woman (aged 76) presented some peculiarities. The arteritis simultaneously interested both superficial temporal arteries; in a second time caused a bilateral "claudicatio masticationis"; induced a worsening of extrapyramidal symptoms from which the patient had been suffering for many years, due to the possible involvement also of the endocranial arteries. The histologic picture on a biopsy of the left temporal artery was typical of the Horton's disease, but without giant cells; the authors suppose that this is due to a therapy with FANS administered before carrying out the biopsy. The patient was treated with cortisone per os at a low dosage, causing a quick regression of the symptoms and a normalization of the laboratory tests. Also this result differs from what most authors have observed: they maintain that Horton's arteritis has become rather resistant to the cortisone therapy and required high dosage for a very long time. The authors maintain that precocity of diagnosis and an immediate treatment can influence in a significant way the course of the disease.