A case of acute thrombosis of the aorta is described; it extended from the superior mesenteric artery to the bifurkation and was probably due to oestrogen medication. The clinical features and diagnosis of this rare condition are described. The condition usually develops against a background of advanced arteriosclerosis and is initiated by certain haemodynamic factors such as intimal damage from blunt trauma, emboli or the thrombogenic effect of oestrogens. The symptoms, such as pain, absent pulses etcetera are the result of ischaemia and depend on the extent of the lesion. A definite radiological diagnosis can only be made by means of aortography, if necessary with oblique projections. The Seldinger technique with a femoral or axillary approach is the method of choice. Aortography shows a filling defect and occasionally a collateral circulation.