Few data are available about elderly patients on peritoneal dialysis (PD). In the present study, we reviewed our experience with patients aged 70 years or more at the start of peritoneal dialysis (PD). This retrospective study was conducted at a single center in Japan. Of 222 patients managed using PD at our hospital between 1991 and 2001 (including 219 cases of PD first), 150 patients were aged under 70 years and 72 patients were 70 years of age or older. For the two groups of patients, we determined clinical data, erythropoietin and PD prescriptions, reasons for selecting PD (elderly patients only), urine and ultrafiltration volumes, comprehensive functional assessment, quality of life (QOL), comorbidity, technique survival rate, and causes of death. Serum creatinine, serum beta(2)-microglobulin, total dose of erythropoietin (EPO) needed to maintain hematocrit at 30%, number of continuous ambulatory peritoneal dialysis (CAPD) exchanges, and total volume of dialysis solution prescribed were significantly lower in the elderly patients as compared with patients aged under 70 years. The main reasons for starting PD in elderly patients at our hospital were advanced age (57%), patient's choice (25%), and cardiovascular complications (9%). Residual renal function was well maintained in CAPD patients aged 70 years or more as compared with patients aged under 70 years. Ultrafiltration volume was lower in the elderly CAPD patients. Scores on the Revised Hasegawa Dementia Scale, the Physical Self-Maintenance Scale, and the Instrumental Activities of Daily Living scale were significantly higher in CAPD patients than in hemodialysis patients. Subjective assessment using a linear analog scale showed a high QOL score in the elderly patients for overall feelings of well-being, mood, and anxiety. At the time of dialysis introduction, the major existing disorders in patients over 80 years of age were mostly cardiovascular disorders such as heart failure, myocardial infarction, serious arrhythmia, and cerebrovascular disease. The median technique survival in patients aged 70 years or more was 31.5 months. The main causes of death in elderly PD patients were heart failure (35.7%), peritonitis (14.3%), and cerebrovascular disease (11.9%). Peritoneal dialysis should be considered the treatment method of choice when introducing dialysis in elderly patients.