Color and pulsed Doppler imaging have assumed a prominent role for evaluating noninvasively lower-extremity arterial occlusive disease. In conjunction with indirect arterial tests, ultrasound imaging is recommended to screen for lower-extremity disease. It provides not only specific information regarding location, severity, and frequency of disease, but it can also determine the optimal therapeutic approach before more invasive procedures. Using ultrasound for graft surveillance is mandatory for identifying flow-reducing lesions that may lead to subsequent bypass failure. As new developments become perfected and clinically available, ultrasound contrast agents, three-dimensional imaging, and B-flow imaging each seem to have great potential for assessing peripheral arterial disease. In all likelihood, these additions will further improve the diagnostic capability of ultrasound and may also lead to the development of new vascular applications for this modality.