A statistical survey of dialysis patients for the year 2006 was carried out for 4051 medical facilities across Japan, and responses were received from 3985 (98.37%) facilities. There were 264 473 dialysis patients (including 9003 peritoneal dialysis patients) in Japan at the end of 2006, which showed an increase of 6708 (2.6%) from the end of 2005. The number of patients per million population was 2069.9. The crude mortality rate during 2006 was 9.2%. The mean age of the patients who began dialysis (in 2006) was 66.4 years, and the mean age of the entire dialysis population was 64.4 years. The primary renal diseases of the patients who began dialysis were diabetic nephropathy (42.9%), chronic glomerulonephritis (25.6%), and nephrosclerosis (9.4%). Of the 3488 facilities that participated in the survey on the dialysate water quality, 2873 facilities (82.4%) measured the endotoxin concentration in the dialysate; and 1197 facilities (37.1%) out of 3228 measured the bacterial count in the dialysate. The mean hemoglobin concentration in the dialysis population at the end of 2006 was 10.23 +/- 1.33 g/dL, which was equal to that at the end of 2005 (10.23 +/- 1.37 g/dL). The mean concentration of serum creatinine in 15 853 patients who started dialysis during 2006 was 8.37 +/- 3.58 mg/dL. The estimated glomerular filtration rate, which was calculated with formula modified for the Japanese population from the Modification of Diet in Renal Disease (MDRD) Study equation, was 5.46 +/- 6.60 mL/min/1.73 m(2).