Atherosclerotic Renal Artery Stenosis is a form or peripheral arterial disease that tends to affect older subjects with hyperlipidemia, history of tobacco use, and who have other coexistent forms of vascular insufficiency. An abdominal bruit on physical exam can be a helpful clue. Slowly progressive, it can lead to critical narrowing of the renal arteries which creates a cascade of events such as renin-angiotensin-aldosterone activation (RAAS), hypertension, acute pulmonary edema, and renal fibrosis. The hypertension is considered a secondary form and can even be resistant to multiple antihypertensives. The diagnosis can be made with imaging (duplex ultrasound CT scans, MRA, or angiography). Because of the unique circulation to the kidney, stenting and angioplasty are rarely curative. This was confirmed in three recent large clinical trials. Therapy consists of lipid and blood pressure control, and dual anti-platelet agents. Because the disease activates the RAAS system, ace inhibitors and angiotensin receptor blockers can be useful agents but carry the risk of ischemic nephropathy, a form of acute kidney injury related to reduced renal blood flow after challenge with these agents. As such these agents are used with caution. Little is known about optimal blood pressure agents or the effect of lifestyle modification.