Health related quality of life (HRQOL) is a useful measure in the analysis of the output of medical interventions in groups of chronic patients like end-stage renal disease (ESRD) patients. From the 1980s to the present day, the interest in evaluating the HRQOL of ESRD patients has been continually growing. A review of published studies shows the existence of important differences in the applied conceptual model of HRQOL, in the assessment instruments used, in the methods of data collection recording, and in the results and conclusions. In this paper we tried to answer some of the main questions which could appear when nephrologists begin to use the HRQOL measures with renal patients: we clearly define the concept of HRQOL; we made recommendations about the instruments to evaluate HRQOL (generic vs specific instruments); and we show how to refine a HRQOL score to make it practical and comprehensible (the standardization of the scores by age and gender).