Questionnaire forms for an annual survey conducted at the end of 2001 were sent out to 3520 institutions, and 3485 replies were received (response rate, 99.00%). According to the survey, the dialysis population of Japan at year end was 219 183 patients, up 6.3% (13 049) over the year before. This equals 1721.9 dialysis patients per million population. The gross mortality rate was 9.3% for the year extending from the end of 2000 to the end of 2001. The mean age of patients beginning dialysis was 64.2 years (+/- 13.7 SD). The mean age of the overall dialysis population in the study year was 61.6 years (+/- 13.1 SD), which was also a higher age than the year before. Among dialysis patients, the primary disease was diabetic nephropathy in 38.1% of patients, slightly down from 39.1% the previous year. Chronic glomerulonephritis was the primary disease in 32.4% of cases, a decrease from 34.7% the previous year. This survey included for the first time the items of the lowest blood pressure during hemodialysis session, vasopressor therapy before dialysis and vasopressor therapy during dialysis session. An analysis of the relationship between the type of vascular access used at the initiation of dialysis and the survival prognosis revealed a significantly higher risk of death in patients undergoing dialysis with synthetic arterio-venous (AV) fistula, AV shunt, or catheter implantation into a central vein than in those receiving dialysis treatments with a native fistula. There was a significantly lower risk of death in the patient group in whom the vascular access was created at 3-6 months before initiation of dialysis than in those in whom such access was created at the time of initiation or within 3 months before the initiation of dialysis. An analysis of the risk factors affecting survival prognosis in maintenance hemodialysis patients showed that risk factors for death are post-dialysis systolic blood pressure over 180 mm Hg and lower than 120 mm Hg, blood pressure elevating progressively from the start to the end of dialysis, serum high density lipoprotein cholesterol concentration of less than 30 mg/dL, and a higher ultrafiltration rate. In comparisons of the death risk between the patient group with a history of intervention for ischemic heart disease and the patient group with a history of myocardial infarction or heart failure but without such intervention, among diabetes patients, those who underwent percutaneous transluminal coronary angioplasty had a significantly lower risk of death than those in whom no intervention was made.