Renal failure in the elderly is currently underestimated and presents a real challenge for the public health system. Kidney function must be routinely assessed by creatinine clearance, estimated with either the Cockcroft and Gault formula or the simplified MDRD formula, which appears especially appropriate for the elderly. Normal kidney aging is related to tissue and functional changes that make older patients very vulnerable to environmental modifications. Numerous factors can accelerate the impairment of rental function during aging. Some of them cannot be modified: sex, genome, and initial kidney disease. Most of them can be managed or treated: hypertension, diabetes mellitus, obesity, smoking, dyslipidemia, proteinuria, and the presence of oxidation and glycation products. Chronic renal failure in the elderly must be managed early with strict treatment targets to avoid the development of end-stage renal disease. Inhibitors of the renin-angiotensin-aldosterone system play an essential role in optimizing nephroprotection: control of hypertension, diabetes complications, and proteinuria. They should be prescribed very carefully in older patients. Age is not a prerequisite for consultations with nephrologists, which should take place early so that nephroprotection can still be useful.