In 49 patients receiving continuous ambulatory peritoneal dialysis, we assessed the relative influences of adequacy of dialysis (assessed by kinetic transfer/volume urea) and psychological symptoms (depression and anxiety) upon the patients' evaluation of their overall quality of life (QoL). Subjects completed self-rating forms for anxiety, depressive, and somatic symptoms, for discrete areas relevant to QoL, and for overall QoL; clinicians also rated QoL. Depressive symptoms proved a much stronger correlate of overall QoL than did the biochemical measure of dialysis adequacy, and they remained influential even after adjustment for anxiety, kinetic transfer/volume, and somatic symptoms. In contrast, the effects of kinetic transfer/volume, anxiety symptoms, and somatic symptoms dropped sharply when adjusted for the other variables. Because psychological (especially depressive) symptoms may be stronger determinants of patients' overall QoL than is adequacy of dialysis, assessing QoL and psychological status should be part of the care of end-stage renal disease patients.