Background:The Korean National Healthcare-associated Infections Surveillance System (KONIS) is a nationwide surveillance network established by the Korean Society for Healthcare-Associated Infection and Prevention in July 2006 to perform healthcare-associated infection surveillance using standardized methods. This report presents the annual data of the intensive care unit (ICU) module of the KONIS system between July 2020 and June 2021. Methods: We performed prospective surveillance of healthcare-associated infections (HAIs), including urinary tract infections (UTIs), bloodstream infections (BSIs), and pneumonia (PNEU), at 339 ICUs in 257 hospitals using the KONIS database. HAI rates and device-associated infection (DAI) rates were calculated as the numbers of infections per 1,000 patient days