Experimental studies have suggested that glomerular hypertension is ultimately damaging to the kidney. Prevention of glomerular hypertension by dietary protein restriction or antihypertensive therapy lessens glomerular injury in several experimental models of chronic renal disease. Glomerular hypertension and hyperfiltration also occur in humans with diabetes mellitus, solitary or remnant kidneys, and various forms of acquired renal disease. Clinical studies are beginning to show that dietary protein restriction and antihypertensive therapy may slow progression in these disorders. Large multicenter trials are currently under way to better define the effects of these therapeutic maneuvers on the progression of chronic renal disease.