Assessment of the quality of life (QoL) of patients with end-stage renal disease undergoing replacement therapy is very important. The aim of our study was to assess the QoL of patients on hemodialysis (HD) and peritoneal dialysis (PD). To determine the state of health of the patients as well as psychological aspects we used two international questionnaires: the Health-Related Short Form (SF-36) and the Psychological General Well-being Index (PGWBI). The study included 48 patients (26 men, 22 women) with chronic kidney disease (KDOQI: 5). All patients were on dialysis treatment. Their mean age was 63 years (range 59-73) and the mean duration of dialysis was 18 months (range 12-34). Twenty-four patients (13 men, 11 women) were on DP and 24 (13 men, 11 women) on HD. The results demonstrate that the PD and HD groups diverged on almost all scales. The scales that measure both the mental and physical dimensions of QoL showed PD to be associated with a higher level of psychophysical well-being than HD. The SF-36 revealed that both the physical and mental dimensions were directly influenced by the type of treatment. On the depression scale of PGWBI we found that patients on HD were more prone to depression than patients on PD. In conclusion, PD appears to have clear advantages in terms of QoL, especially in elderly patients, thanks to the possibility to perform the treatment independently at the patient's home.