This review will address five selected conditions associated with variable degrees of renal insufficiency or renal failure. Early diagnosis, usually possible in the office setting, should encourage early treatment and/or referral that will be rewarded by substantial improvement or return of normal renal function. Hypertensive nephrosclerosis, particularly among black Americans, is now the second leading cause of end stage disease (ESRD) in the United States. Aggressive treatment of hypertension can prevent progression to renal failure. Obstructive uropathy is relatively common at all ages; if not corrected, it can progress insidiously, often without symptoms, to destruction of a kidney. Glomerulonephritis may involve the kidneys primarily or in association with a multisystem disorder. Early renal biopsy will help establish the pathologic diagnosis and guide subsequent therapy. The kidney is vulnerable to the nephrotoxic effects of numerous pharmacologic agents used commonly in the diagnosis and treatment of illness. Potential nephrotoxicity to a given class of agents must be recognized if progressive nephrotoxicity is to be avoided. Finally, the frequency of occlusive renovascular disease and ischemic nephropathy is on the rise as the US population increases in age. Several interventions are available for the treatment of ischemic nephropathy and for the prevention of ESRD associated with bilateral renal artery occlusion.