Background: Patients undergoing liver transplantation (LT) are at high risk of peri‐operative complications that can lead to rapid clinical deterioration (RCD). The Rapid Response System (RRS) facilitates timely escalation of care for patients identified as high‐risk for RCD, using abnormal observations and vital signs (Table 1) to activate a medical emergency team (MET). The prognostic significance of MET activation is poorly studied in LT patients. We investigated the epidemiology of MET activations in LT patients and the association between MET activation and outcomes. Methods: Patients receiving MET activations pre‐ or post‐LT (in the same admission as LT) were identified from a prospectively collected database of patients undergoing LT at the Victorian Liver Transplant Unit over 84‐months (2011‐2017). Primary outcomes were mortality, length of stay (LOS) and unplanned readmission to ICU Results: 383 patients were included. Median age was 56 years (IQR 48 ‐ 61), 65% were male and median MELD score was 18 (IQR 11 ‐ 26). 131 (34%) patients had ≥1 MET activation, with a total of 266 MET activations recorded (MET event rate 695 per 1000 LT admissions). 106 MET activations occurred in 59 patients pre‐LT (pre‐LT MET) and 160 in 88 patients post‐LT (post‐LT MET). Commonest triggers for MET activation were tachypnoea and hypotension pre‐LT and tachycardia post‐LT. MELD scores were significantly higher in the pre‐LT MET cohort compared to the no‐ and post‐LT MET groups (MELD 27 vs. 16 and 20, p<0.001). Unplanned ICU readmission rates following a pre‐LT and post‐LT MET activation were 35% and 17% respectively. Of patients readmitted to ICU, 48% and 25% had fulfilled MET activation criteria for >4 and >12 hours prior to MET activation respectively. MET patients had significantly longer ICU LOS (no‐MET 65 hours vs. post‐LT MET 110 hours (p<0.001) and vs. pre‐LT MET 136 hours (p<0.001)) and hospital LOS (no‐MET 13 days vs. post‐LT MET 23 days (p<0.001) and vs. pre‐LT MET 24 days (p<0.001)). In‐hospital survival was 96% and did not differ between groups. MET patients were significantly more likely to require inpatient rehabilitation (no‐MET 15% vs. post‐LT MET 41% (p<0.001) and vs. pre‐LT MET 56% (p<0.001). Conclusion: LT patients with peri‐operative complications prompting MET activation represent a high‐risk group with increased morbidity, ICU and hospital LOS. Early identification and correction of factors which predispose to MET calls may lead to improved outcomes and a reduction in health‐care costs.