BACKGROUND Although renal-replacement therapy for children with end-stage renal disease has been used for several decades, data on patients' long-term survival are sparse. METHODS We examined the long-term survival of all children and adolescents who were under 20 years of age when renal-replacement therapy commenced (study period, April 1963 through March 2002), using data from the Australia and New Zealand Dialysis and Transplant Registry. Survival was analyzed with the use of Kaplan-Meier methods and age-standardized mortality rates. Risk factors for death were analyzed with the use of Cox regression analysis with time-dependent covariates. RESULTS A total of 1634 children and adolescents were followed for a median of 9.7 years. The long-term survival rate among children requiring renal-replacement therapy was 79 percent at 10 years and 66 percent at 20 years. Mortality rates were 30 times as high as for children without end-stage renal disease. Risk factors for death were a young age at the time renal-replacement therapy was initiated (especially for children under 1 year of age, among whom the risk was four times as high as for children 15 to 19 years of age) and treatment with dialysis (which was associated with a risk more than four times as high as for renal transplantation). Overall, a trend toward improved survival was observed over the four decades of the study. CONCLUSIONS Despite improvement in long-term survival, mortality rates among children requiring renal-replacement therapy remain substantially higher than those among children without end-stage renal disease. Increasing the proportion of children treated with renal transplantation rather than with dialysis can improve survival further.