There is an ongoing trend of a rapid increment in the frequency of diabetes mellitus, expecially the non-insulin dependent form. By the end of the 2nd millenium 150 million cases were recorded worldwide, while the estimations predicted doubling the number by the year 2030. Numerous chronic complications accompany the disease, among them micro-, as well as macrovascular prevail, affecting small and large blood vessels. This paper provides a literature review on the topic of diabetic nephropathy, the main microvascular complication of diabetic disease. Microalbuminuria is the earliest sign of the diabetic renal involvement, with more than 30 mg and less than 300 mg of albumins in 24 h urine sample. The reduction of renal function begins with albuminuria leaving microalbuminuria level and entering the pathologic proteinuria range. Renal failure advances through the 5 stages, the final fifth occurring fortunately only in a minor proportion of the patients. The final stage ensues in 232 of 100 000 diabetic patients, according to the US data. However, in many developed countries there are 30-40% of new patients entering chronic dialysis treatment for diabetic nephropathy. Pathogenesis of diabetic nephropathy is based on hyperglycemia and distinct hemodynamic changes, glomerular hyperfiltration and high intraglomerular pressure. The important role have oxidative stress, advanced glycation end products, some cytokines, growth factors and sorbitol pathway. Nevertheless, genetic influence is considered by far the most important risk factor for diabetic nephropathy. Heritage determines the susceptibility in one and the protection in another diabetic patient. At the moment of pathologic proteinuria occurrence, glomerular filtration rate begins to decline for 1.2 ml/min/monthly in some patients, making the annual reduction of 7-14 ml/min/1.73 m2 of body surface area. Improving glycemia, blood pressure control, renal anemia correction with rHu-Epo, dyslipidemia control, reduction in protein intake, i.e. management of the nongenetic factors, could slower the renal function loss in some of the patients. Hence, these measures could reduce the proportion of the patients reaching end-stage renal disease, having in mind that morphological and functional changes are reversible only within certain limits. Therefore, the success of kidney protection is better if commenced earlier.