The majority of patients with hypertension have one or more additional risk factors for cardiovascular disease. In planning an appropriate treatment program, it is useful to identify and stratify hypertensive patients according to their risk of developing cardiovascular, cerebrovascular, or renal disease. At particular risk are the elderly, patients with diabetes, and those with target-organ damage manifested by impaired renal function. Evidence supports increased risk in these patients, and clinical trial results demonstrate the considerable benefits realized through aggressive blood pressure (BP) control. The number of elderly individuals continues to increase in the United States and other industrialized countries. The prevalence of isolated systolic hypertension (ISH) is higher in the elderly than in younger individuals. ISH is associated with significant morbidity and mortality and should not be considered a physiologic manifestation of the normal aging process. Type 2 diabetes is also increasing in prevalence. Patients with diabetes are at increased risk for coronary heart disease, stroke, renal failure, and other cardiovascular complications. Aggressive treatment of elevated BP can produce dramatic decreases in the cardiovascular complications of diabetes. The incidence of end-stage renal disease has increased 2.5-fold in the past two decades, and poorly controlled BP is a major contributor to the increase. Lowering BP to levels well below the traditional goal of 140/90 mm Hg is needed to slow the progression of renal dysfunction and prevent renal failure in hypertensive patients with renal disease, whether related to diabetes or to another etiology. Aggressive treatment of hypertension in multiple-risk populations (to the goals of JNC VI and the recent WHO-ISH Guidelines for the Management of Hypertension) can be expected to produce significant reductions in the incidence and prevalence of stroke, heart failure, coronary heart disease, chronic renal failure, and total cardiovascular mortality. © 1999 American Journal of Hypertension, Ltd.