Aortic dissection and aneurysm are related to increased vulnerability of the aortic wall due to arteriosclerosis. Echographic findings of aortic sclerosis include irregularity and strong punctate echoes in the intima and meandering of the aorta. Unruptured abdominal aneurysms are often found incidentally by routine echography. The "maximum diameter" and "increase in the size" of aortic aneurysm on echography are important information closely related to the risk of its rupture. In the evaluation of acute aortic dissection, the flap length indicates the range of dissection. The presence or absence of blood flow in the false lumen must be examined simultaneously using color Doppler echography. Some aortic dissections and aneurysms require emergency treatment on detection, and the evaluation of their images on echography, which is often performed for screening of patients with back or abdominal pain, are important for the determination of the therapeutic approach. In patients who are treated conservatively or observed, echography is very useful for the follow-up. Such patients must also be diagnosed or followed up by combining echography with other imaging techniques depending on the condition and necessary information in each patient.