Despite the variety of possibilities to evaluate hemodynamics, ultrasound-in particular duplex sonography-is the method of choice. With an increasing number of endovascular procedures, intraoperative angiograms will remain indispensable. The method of angioscopy is reserved for individual cases. Indirect monitoring in carotid surgery will keep its significance. This includes measuring somatic evoked potentials as well as transcranial duplex sonography, with regard to the increasing importance of plaque morphology and possible neurological consequences. The general recommendation of applying at least one intraoperative control method is necessary in carotid surgery, even if intraluminal shunts are routinely implanted. In addition, quality control of the peripheral vascular system should be sufficiently documented by using one or more methods of examination. So far, in prospective randomized trials, results have not improved by applying intraoperative monitoring methods. Nevertheless, they are indispensable for the careful vascular surgeon and can help to avoid complications and revision with worse prognosis in some cases.