To evaluate information on the prevalence and rate of progression of atherosclerotic renovascular disease and the effect of angiotensin-converting enzyme inhibition on this process, with the goal of developing a rational approach to the diagnosis and management of this disorder. Relevant articles were identified from the authors' files and from MEDLINE searches. Additional references were obtained from the bibliographies of identified articles. Virtually no controlled prospective studies have been reported. The articles presented are primarily retrospective analyses and include those that provide sufficient information about the incidence or progression of renovascular disease and about the outcome and mortality rate associated with various treatments, to allow evaluation. For the outcomes of interest, data from individual reports are presented in tabular form, the results summed, and averages obtained. Atherosclerotic renovascular disease, in many cases involving both renal arteries, is a common finding in patients older than 50 years, particularly those with diffuse atherosclerotic vascular disease. Hypertension is not a particularly sensitive indicator of this disease (almost one half are not hypertensive). The disease progresses and may account for 5% to 15% of all patients developing end-stage renal disease each year. Angiotensin-converting enzyme inhibition may damage ischemic renal tissue, but this is counterbalanced by beneficial effects of this therapy. Once end-stage renal disease is present, mortality rates are high despite dialysis support (> 50% over 3 years). Both surgery and angioplasty can preserve or improve renal function and may delay or prevent the need for dialysis therapy. These invasive procedures may have lower rates of morbidity and mortality than the so-called "conservative" approach of dialysis therapy when renal failure develops. Given available information, diagnosis and intervention should be considered seriously in patients at high risk for renovascular disease who have clearly progressing renal insufficiency. Prospective trials are needed, however, to determine the costs and benefits of each approach to treatment in all patients with renovascular disease and renal insufficiency.