PURPOSETo describe the incidence and mortality of upper tract urothelial carcinoma (UTUC) from 2002-2020 using data from the Korean National Health Insurance Service, which contains data from the entire Korean population.MATERIALS AND METHODSReimbursement records for 43,255 patients diagnosed with primary UTUC (according to the International Classification of Disease 10th revision code C65 and C66) between 2002-2020 were retrieved. The study period was split into four: period I (2002-2005), period II (2006-2010), period III (2011-2015), and period IV (2016-2020). Trends were quantified by calculating the annual percentage change (APC). Mortality data were obtained from the Statistics Korea.RESULTSFrom 2002-2020, the incidence of UTUC in Korea increased gradually from 9.34 to 11.40 per 100,000 person-years. Although there was a male predominance, the male to female ratio did not change significantly over time; however, age at the time of diagnosis, the comorbidity index, and the proportion of patients undergoing open/laparoscopic surgery increased significantly over time. There was a modest improvement in 5-year survival (both all cause- and cancer-specific) over the study period. Multivariate analysis identified age at diagnosis, sex, the comorbidity index, and open/laparoscopic surgery as being associated with survival.CONCLUSIONSBetween 2002 and 2020, the incidence of UTUC in Korea showed a general upward trend; however, survival outcomes have improved. These representative datasets from the Korean population might provide crucial information that enables clinicians to better understand of the epidemiology of UTUC in Korea.