Introduction This study analyzed data from the End Stage Renal Disease patient registry collected by the Korean Society of Nephrology to explore trends in mortality among dialysis patients from 2001 to 2022. Method Mortality was analyzed in two ways: firstly, using the annual mortality rate, and secondly, by assessing survivability after a certain period of time since the initiation of dialysis. Additionally, we categorized the causes of death by disease group annually to observe how the proportions changed. Results Since 2001, annual mortality for dialysis patients generally declined, except for a rise in 2020 and 2021 among hemodialysis patients. Overall mortality rates for all dialysis patients dropped from 74.2/1,000 person-years in 2001 to 42.3/1,000 person-years in 2022, with a more pronounced decrease in peritoneal dialysis. While survival probability over the five years following initiation of dialysis has shown a steady increase, short-term mortality from 2018 to 2020 affected by COVID-19 has shown a yearly increase by age group, with a greater effect in those aged 75 years and older. The leading causes of death for all dialysis patients have changed little, in the order of heart disease, infection, and vascular problems Summary While annual mortality and survival probability after dialysis initiation have generally improved in dialysis patients, there has been a temporary deterioration during the COVID-19 pandemic, most pronounced in the elderly.