The prevalence and incidence of end stage renal disease has increased considerably in the past years. We know that the cost of treatment of these patients is high. Limited information exists on care resource utilization for maintenance of patients before the initiation of replacement therapy. The purpose of this study is determine the cost of pharmaceutic treatment during the predialysis phase. Pharmacy cost was analyzed for 200 patients controlled on outpatient nephrology department. The mean age was 72.4 years, 59% were males, and the comorbidity distribution was: hypertension 87%, hyperlipidemia 56% and diabetes 35%. The per-patient-per-month charges were 215.45 Euro, with a continous increase from 84.64 Euro on stage 1 to 352.59 Euro on stage 5 of chronic kidney disease. Erythropoiesis stimulants were reponsible of 46.5% of these cost. The most frequent prescribed medications were antihypertensive drugs, statins and iron preparations. Patients with end stage renal disease generate significant cost during the predialysis period. The limited resources, and the growth of health care expeditures, particulary the spending for prescriptions drugs, are two of the major problems for Health Care Systems. A better knowledge of the associated costs to the treatment of these patients will help us to increase our efficiency.