KSN ESRD Registry Report 2021-survival analysis The End-stage Renal Disease Registry (ESRD) Committee of the Korean Society of Nephrology (KSN) collects data on the dialysis therapy in Korea through an internet-based registry program and reports it annually. We conducted analyses using administrative data over the period 1 January 2001–30 April 2021 in the outpatient dialysis facilities. • The crude all-cause mortality in prevalent patients receiving hemodialysis (HD) decreased from 79.7 per thousand patient-years in 2011 to 19.6 in 2020. In PD patients the mortality rate decreased from 73.9 to 24.1 per thousand patient-years, respectively in 2011 and 2020. The crude mortality rates were steadily declined in both HD and PD patients. and the difference of mortality rates between HD and PD patients decreased in the past ten years. However, the mortality rates in PD patients was higher than in HD patients since 2018. • Female receiving dialysis had substantially lower mortality rates than male for all age groups. • Among patients receiving dialysis, survival improved in successive incident cohorts from 2005 to 2015. The improvement was even greater for patients initiating PD. • The mortality rate decreased in parallel over time across all age groups. The crude mortality rate in dialysis patients aged over 75 years was more than 6 to 8-fold higher than the rate in dialysis patients aged 18-44 years. • The most common cause of death in HD patients was cardiac-related (34.8%), and the next cause was infection (23.6%).