The principles of ultrasound diagnosis are briefly explained and the technique of the examination is described with particular reference to the measures taken to ensure the exact measurement of diameters. The modalities for the echographic presentation of the normal and aneurysmatic aorta is illustrated, together with the respective pictures. It is suggested that echography be employed both as a preliminary technique and as a supplement to angiography, which is not itself particularly applicable in the case of aneurysms. Above all, it can be considered as the sole and resolutive examination on account of the findings it offers.