h mortality in hospitalized patients with cirrhosis and AKI-RRT in a multicentric contemporary cohort. Methods: This is a multicenter retrospective cohort study using data from the HRS-HARMONY consortium, which included 11 U.S. hospital network systems. Consecutive adult patients admitted in 2019 with cirrhosis and AKI-RRT were included. The primary outcome was 90-day mortality, and the main independent variable was AKI etiology, classified as hepatorenal syndrome (HRS-AKI) vs. other (non-HRS-AKI). AKI etiology was determined by at least two independent adjudicators. We performed Fine and Gray sub-distribution hazard analyses adjusting for relevant clinical variables. Results: Of 2,063 hospitalized patients with cirrhosis and AKI, 374 (18.1%) had AKI-RRT. Among these, 65 (17.4%) had HRS-AKI and 309 (82.6%) non-HRS-AKI, which included ATN in most cases (62.6%). Continuous RRT (CRRT) was used as the initial modality in 264 (71%) of patients, while intermittent hemodialysis (IHD) was util