Arterial hypertension is most often the first symptom of renal artery stenosis (RAS). Appropriate screening methods for the diagnostic workup of hypertension are colour-coded duplex ultrasound and captopril scintigraphy. Angiography (intraarterial digital subtraction angiography) represents the diagnostic "gold standard", which is the prerequisite for the selection of the most suitable therapeutic method. Atherosclerosis is the most common disease in elderly patients presenting with RAS. In younger patients, fibromuscular dysplasia is more frequent. Five main types with different prognosis and therapeutic indications can be classified. Rare causes of RAS are dissection, renal artery aneurysm with combined stenosis, and especially in children and adolescents middle aortic syndrome with hypoplasia of the visceral arteries. Every patient with RAS of hemodynamic relevance in the presence of hypertension should be treated, whereas therapeutic risk and benefit must be weighed up individually. Aims are the improvement of hypertension and the maintenance of renal function. Surgical techniques, which are described subsequently, are indicated in all patients who need further simultaneous treatment of the abdominal vessels (abdominal aortic aneurysm, aortoiliac or visceral artery stenosis or aneurysm, respectively). In atherosclerotic ostial stenoses, angioplasty (PTA) and open surgery (normally transaortic endarterectomy) are concurrent methods. In our experience, the long-term results of surgical reconstruction seem to be superior. Both procedures are subject to an ongoing randomized study in our department. The outcome of surgical treatment for RAS is satisfying, the operative risk especially in isolated renal artery lesions is negligible.