To examine how patient survival substantiates dialysis adequacy, 20-year actuarial survival experience was calculated for 445 unselected hemodialysis (HD) patients (97 patients accepted on a temporary basis--and usually kept on their regular dialysis scheme--were left out). The dose of dialysis has been the same and unchanged for all patients since beginning: 24 square meter hours of Kiil dialysis (cuprophane) per week with acetate buffered dialysate. KT/V mean (SD) was 1.67 (0.41). Six months after starting dialysis, 98% of patients were normotensive and off all blood pressure (BP) medication. The mean population hematocrit, excluding the only 6 patients receiving erythropoietin supplementation, was 28%. Survival rate was 87% at 5 years, 75% at 10 years, 55% at 15 years, and 43% at 20 years of HD. The satisfactory control of BP without using potentially toxic BP drugs and the higher than usual dose of dialysis are two possible explanations for survival data better than usually reported. We suggest that patient survival should be considered as the best overall index of adequacy of dialysis.