An increasing number of population-based studies and clinical trials have examined the role of blood pressure in renal disease. Recent reports indicate that elevations of blood pressure, even within the normotensive range, may result in renal damage. The available evidence suggests that blood pressure reduction diminishes and may completely prevent the progressive deterioration of renal function in persons with established renal insufficiency. Blood pressure reduction with an angiotensin-converting enzyme inhibitor may provide the best means of achieving this goal, but other antihypertensive medications may be equally effective. Nonpharmacologic interventions can be used to lower blood pressure in hypertensive persons and prevent the development of hypertension in those with blood pressure in the high-normal range. Other recent studies examined the role of environmental nephrotoxins, unrecognized viral infections, lower socioeconomic status, access to health care, and genetic factors as determinants of renal disease and hypertension in the general population. Despite their overall importance, known risk factors for hypertension-related renal disease fail to explain the excess risk of this entity in blacks and other racial minorities.