A 36-year-old woman was delivered to our hospital with suspected aortic dissection from an outlying hospital in May 1994. She reported a history of acute and persistent thoracic and epigastric pain. The physical examination revealed a minor senso-motorical palsy of the left side as residuum after minor strokes occurring 12/93 and 4/94. Also, a marked hypertension (170/100 mm Hg) was present. The hematologic and blood chemical values were normal with a white cell count of 12,000, an erythrocyte sedimentation rate (ESR) of 19 mm/h and a c-reactive protein (CRP) of 2.2 mg/dl. The electrocardiogram was normal. Transthoracic- and transesophageal-echocardiography (TTE, TEE) revealed an eccentric thickening of the whole wall of the descending aorta up to the bifurcation with a stenosis at the side of the diaphragma. Those findings were confirmed by computed tomography. Because of the acute onset of symptoms and the results of the imaging procedures aortic dissection de Bakey type III was diagnosed and the patient was treated with beta-blockers. Symptoms were relieved over the following days. After 2 days a pleuric effusion developed and all inflammatory tests rose (fibrinogen 780 mg/dl, ESR 80 mm/hr, CRP 16 mg/dl). At this time the differential diagnosis of an arteritis was considered. A new TEE-study demonstrated no change, but now more attention was given to the fact that no dissection membrane could be visualized and all wall structures were thickened. In combination with the history of cerebral infarction due to carotid obstruction and the elevated laboratory values the diagnosis of Takayasu-aortitis was established and corticoid therapy was started. Within a few weeks the arterial changes diminshed markedly and the woman became free of symptoms. This case demonstrates the rare situation of an arteritis mimicking aortic dissection, in which the clinical course revealed the true diagnosis.