Atherosclerotic renal arterial disease (ARAD) is becoming a more important cause of end-stage renal failure. Diagnosis is more easily achieved because of greater clinical suspicion and more refined screening tools. However, the medical and interventional management of patients with ARAD is not well defined in the literature because there have been few randomized trials. Because the use of angiotensin-converting enzymes (ACE) inhibitors, and more recently angiotensin-antagonists, has become much more widespread, it is inevitable that we should, knowingly or not, give these drugs to patients with ARAD. We describe 2 case studies in which the angiotensin-antagonist irbesartan was given to 2 patients with effectively single-functional kidneys after successful renal arterial radiologic intervention. The rationale for the use of irbesartan was to control BP, which had not responded to the initial arterial intervention, and took place in patients both refractory to, and intolerant of, many other anti-hypertensive drugs. Irbesartan successfully and safely reduced systemic BP, measured by use of ambulatory BP, without prejudicing renal function (measured by use of individual kidney function GFR).