A reduction in the diameter of the renal arteries can lead to hypertension, renal dysfunction and/or pulmonary edema. About 90% of patients with renal artery stenosis have atherosclerosis, and 10% have fibromuscular dysplasia. Atherosclerotic renal artery stenosis is a common condition that typically occurs in patients at high risk of cardiovascular disease with coexistent vascular disease at nonrenal sites. Patients who undergo revascularization to treat hypertension associated with atherosclerotic stenosis need to continue medication with statins, antiplatelet agents and renin-angiotensin antagonists after the procedure to prevent renal and cardiovascular events. Two recent trials compared renal outcomes in patients with atherosclerotic stenosis who were treated with antihypertensive medication plus stenting with those in patients who were treated with medication alone. Available results favor a conservative approach (medication only) for most patients with atherosclerotic renal artery stenosis. These results, however, concern patients with stable clinical conditions and, in many cases, only moderate renal artery lesions. Blood pressure outcome after angioplasty is more favorable in patients with fibromuscular renal artery disease, who usually do not have renal failure, than in those with atherosclerosis.