The authors report a case of an acute aortic dissection in a sixty year old patient who two months previously had an ischemic cerebral vascular accident. On the basis of a remittent fever and of raised acute phase proteins the authors suspected a giant cell arteritis as possible pathogenic cause of the clinical presentation. Ruled out infective and neoplastic disorders, after an unhelpful temporal artery biopsy, steroid treatment was introduced at the recommended dosage. Three months after, while reducing steroid therapy, the acute phase proteins raised again to come back to normal values only after restoring full steroid dosage. This pattern of response to steroid treatment may further support the diagnosis of giant cell arteritis even after an unhelpful temporal artery biopsy.