Introduction. Acute Physiology and Chronic Health Evaluation (APACHE) II and III and Sequential Organ Failure Assessment (SOFA) are prognostic scores commonly used in the intensive care unit (ICU). Their accuracy in predicting mortality has not been adequately evaluated in comparison to prognostic scores commonly used in critically ill cirrhotic patients with acute decompensation (AD) or acute-on-chronic liver failure (ACLF). Aims. This study was conducted to evaluate the performance of prognostic scores, including APACHE II, SOFA, Chronic Liver Failure Consortium (CLIF-C) SOFA, Child–Turcotte–Pugh (CPS), Model for End-Stage Liver Disease (MELD), MELD-Na, MELD to serum sodium ratio (MESO) index, CLIF-C organ failure (CLIF-C OF), CLIF-C ACLF, and CLIF-C AD scores, in predicting mortality of cirrhotic patients admitted to the ICU. Patients and Methods. A total of 382 patients (280 males, mean age 67.3 ± 10.6 years) with cirrhosis were retrospectively evaluated. All prognostic scores were calculated in the first 24 hours of ICU admission. Their ability to predict mortality was measured using the analysis of the area under the receiver operating characteristic curve (AUC). Results. Mortality was observed in 31% of the patients. Analysis of AUC revealed that CLIF-C OF (0.807) and CLIF-SOFA (0.776) had the best ability to predict mortality in all patients, but CLIF-C OF (0.749) had higher prognostic accuracy in patients with ACLF. CLIF-SOFA, SOFA, and CLIF-C AD had the highest AUC values in patients with AD, with no statistical difference (
p
=
0.971
). Conclusions. When compared to other general or liver-specific prognostic scores, CLIF-C OF, CLIF-SOFA, SOFA, and CLIF-C AD have good accuracy to predict mortality in critically ill patients with cirrhosis and patients with AD. According to the clinical scenario, different scores should be used to provide prognosis to patients with cirrhosis in the ICU.