Diabetic nephropathy is the most frequent cause of end stage renal disease (ESRD). As ESRD incidence increases continuously, more resources are needed for treatment. The objective was to evaluate the economic impact of losartan added to the standard care administered to diabetic subjects with ESRD. The analysis has involved more than 500 million inhabitants. Standard methods have been used in order to conduct an economic evaluation comparing the economic outcomes deriving from the administration of losartan added to standard care versus standard care alone in patients with type 2 diabetes mellitus (DM) and nephropathy over 3.4 years. The study was hence conducted from the perspective of the third-party payer. The clinical outcome data were based on the results from the Reduction of Endpoints in Non-Insulin Dependent Diabetes Mellitus with the Angiotensin II Antagonist Losartan (RENAAL) trial. Direct medical costs are referred to the purchase costs of losartan and to the costs of hospitalization. The costs were discounted back at an annual rate of 3%. Also sensitivity analysis was performed. The RENAAL study showed that losartan confers strong renal protection in patients with DM and nephropathy. Losartan results into cost saving in all countries considered: 3,602.98€/Italy, 4,531.35€/France, 3,019.66€/Germany, 3,949.50€/Switzer-land, and 3,855.50€/US per patient. Results are not sensitive to both clinical and economic variables. In addition to the medical benefits, this analysis demonstrates the economic relevance of the treatment with losartan in DM patients affected by nephropathy.