The aim of the present paper is the economic evaluation of haemodialysis in a dialysis unit of a private clinic. Specifically, a comparative cost analysis between bicarbonate dialysis and haemodiafiltration is performed. One hundred and twenty (120) patients with end - stage kidney disease, undergoing haemodialysis participated in the study. Demographic, clinical and financial characteristics were taken from the patients’ medical records. Data were collected from the financial management of the clinic regarding staff salaries, capital and technological equipment, depreciation, expenditure on fixed assets and other consumables. Values of 2007 were used and haemodialysis session was considered as the unit of cost. The total cost of haemodiafiltration predominates by about 30% of bicarbonate dialysis. This significant increase in cost is due to the additional health equipment required in this method (bags and lines of haemodiafiltration). Haemodialysis is a highly expensive method of treating patients with chronic kidney disease, as based mainly on the use of innovative technologies. Similar analyses of economic evaluation are not considered fully documented, when not taking into account the clinical superiority and not attributing it in terms of cost - effectiveness.