Diabetic nephropathy is an important problem in insulin-dependent diabetic patients. Directly or indirectly it is a major cause of death amongst them and accounts for a great number of patients requiring renal replacement therapy today. The last decade has seen a considerable growth in the insight into the pathophysiological mechanisms underlying the development of diabetic renal disease. In this article, the current knowledge concerning the pathogenesis of diabetic nephropathy and the implications of this understanding for therapeutic approaches will be discussed.