Aortography, venography, and angiocardiography are generally accepted as valuable diagnostic procedures. Aortography is often employed for aortic or peripheral arterial vascular disease and for investigation of the arteries supplying the kidneys and other abdominal organs and tumors. Many contrast media have been used since the early report of use of sodium iodide for arteriography by Dos Santos. Lamas, and Pereira,1 in 1929. Melick, Byrne, and Boler2 in 1952 compared several iodine compounds and found sodium iodide more toxic than iodopyracet (Diodrast). They considered sodium acetrizoate (Urokon Sodium) least toxic. Sodium acetrizoate is commonly used in a 70% solution for aortography and in a 35% solution for femoral arteriography or for venography. Iodopyracet is generally recommended in a somewhat less concentrated solution. The few serious complications which have occurred with aortography have been caused by injury of organs which re ceive their blood supply directly from the lower aorta.