BACKGROUND: So far, little attention has been paid to the value of dialysis adequacy for patients' quality of life (QL). Therefore we studied the impact of demographic, clinical, and dialysis characteristics on physical symptoms and perceived QL. METHODS: The study population consisted of 120 incident chronic haemodialysis (HD) and 106 peritoneal dialysis (PD) patients, starting dialysis treatment in 13 Dutch centres. Data were collected 3 months after the start of dialysis. Nine physical symptoms were assessed with a self-administered questionnaire. Patient's self-assessment of QL was measured with the 36-item MOS Short Form (SF-36). RESULTS: The most common symptoms in HD and PD were fatigue (respectively 82 and 87%) and itching (73 and 68%). In HD only a medium to high comorbidity--age risk index was associated with greater symptom burden. In PD also a lower percentage lean body mass, a lower rGFR, and past episodes of underhydration were associated with greater symptom burden. The explained variance by these variables was only 12% in HD and 21% in PD. However, greater symptom burden explained a substantial additional amount of impaired physical and mental QL on top of demographics and clinical status. Dialysis variables were associated neither with symptoms nor with QL. CONCLUSION: Symptom burden can be explained to a limited extent by demographic and clinical variables and not by dialysis characteristics. Addition of symptom burden to the other variables makes it possible to explain one-third of perceived QL. This underlines the importance of symptom reduction in order to improve patient's QL.