Background and aims: Patients undergoing liver transplantation (LT) have a high-risk of postoperative clinical deterioration (CD). Previous studies indicate that 6–19% LT recipients require unplanned intensive care unit (ICU) readmission, which most commonly occurs following Rapid Response Team (RRT) activation and is associated with morbidity and mortality. There is a paucity of data on predictors of unplanned ICU admission following RRTactivation post-LT.We aimed to determine the incidence and factors predicting unplanned ICU admission post-LT. Method: We conducted a cohort study of consecutive LT recipients (≥18 years) of the Victorian Liver Transplant Unit who experienced a CD event and RRT activation from 2011–2017. The primary outcome was unplanned ICU admission. Secondary outcomes were hospital length of stay (LOS) and inpatient mortality. Multivariable logistic regression with cluster specific robust standard errors was used to predict the primary outcome, while accounting for baseline variables, RRT triggers, biochemistry and vital signs. Models were compared with information criteria. Model discrimination was assessed by the area under the receiver operating curve (AUROC) and calibration examined by a calibration plot. Results: 381 patientswere included. Median agewas 56 (IQR 48–61), 65% were male and mean MELD score was 19 (SD 9.6). Post-LT CD occurred in 88 (23%) patients with a total of 160 RRT activations at a median of 11-days (IQR 5–23) post-LT. Unplanned ICU readmission occurred in 16.9% (27 of 160) of RRT activations, or 6.0% (23 of 381) transplant recipients. Variables independently associated with unplanned ICU admission in the regression model are listed in Table 1, which predicted the primary end point with an AUROC of 0.82. Compared to patients without ICU readmission, patients with unplanned ICU admission had longer post-LT LOS (median, 23 days vs 13 days, p < 0.001), ICU LOS (median,189 hours vs 72 hours, p < 0.001) and a non-significant trend towards higher mortality (13.0% vs. 3.6%, p = 0.06). No difference in mean MELD at time of LT was noted between groups (21 vs. 19, p > 0.05). Conclusion: LT patients with CD requiring unplanned ICU readmission are a high-risk group with increased morbidity, ICU and hospital LOS. We identified a model that predicted ICU readmission with an AUROC of 0.82, however further validation is required. Early identification and correction of these factors may lead to improved outcomes and a reduction in health-care costs.