Percutaneousl US including carotid ultrasonographic examination is a promising noninvasive method for evaluating atherosclerosis and is finding increasing use in clinical settings. Atherosclerosis comprises two components: atherosis and sclerosis. Ultrasonography can be used to evaluate atherosis and sclerosis simultaneously: atherosis being assessed based on intima media thickness; sclerosis, by stiffness parameter. Moreover, recently developed ultrasound systems often provide tracking systems that can calculate stiffness parameter automatically. Therefore, surface echo, especially that observed in carotid ultrasonography, is useful in evaluating atherosclerosis. Further, percutaneousl US examination also has a place in treating peripheral artery disease PAD. New techniques and devices for percutaneous peripheral intervention PPI have been developed, while interventional cardi ologists use percutaneous peripheral intervention to treat more diffi cult cases of peripheral artery disease. Percutaneousl US guidance effectively decreases exposure to radiation and improves the success rate in percutaneous peripheral intervention. An ultra sound unit is thus essential in the catheter laboratory when carrying out surface echo guided percutaneous peripheral intervention. These facts support the conclusion that percutaneousl US is a valuable tool in evaluating atherosclerosis as well as in performing per cutaneous peripheral intervention to treat it.