While aging is accompanied by many age-related changes in renal physiology and function, proteinuria should not be considered to be a part of “normal aging”. There are many age-prevalent illnesses that predispose one to developing proteinuria and early recognition, and treatment may help retard disease progression or offer an early cure. The presence of proteinuria warrants further evaluation and follow-up if one has any hope of avoiding its progression and delaying the initiation of treatment. This review article will discuss the anatomy and physiology of the aging kidney, the pathophysiology and etiology of proteinuria during later life, methods to evaluate proteinuria, and ways to monitor and manage this problem.