Background: Serum lactate level can be used as an important predictor of short-outcomes in critically ill patients with complicated liver cirrhosis. Objective: To improve risk prediction and better assessment of short-term outcomes of ill critically cirrhotic, through assessment of serum lactate level on ICU admission and after 24 hours. Patients and methods: This observational descriptive cohort study included 151 critically ill patients with decompensated liver cirrhosis who were admitted into ICU of Zagazig University Hospitals. Results: Causes of admission to ICU included hepatic encephalopathy (34.4% of cases), bleeding esophageal varices (33.8%), hepatorenal syndrome (23.2%), SBP (7.3%) and hepatopulmonary syndrome (1.3%). Serum lactate levels were 14.5 ± 8.6 and 14.2 ± 9 mmol/L on admission and 24 h after admission to ICU, respectively. These figures are much higher than figures in a healthy population and in patients with compensated cirrhosis. Serial measurement of serum lactate showed a tendency toward elevation in 43.7% of patients, and a drop in 50.3%, 24 h after admission, with the remaining 6% of cases being unchanged. ICU mortality was encountered in 33.8% of patients. Conclusion: In critically-ill patients with liver cirrhosis, lactate levels were independently related with short-term mortality and indicate the severity of the illness and organ failure. Measures that decrease serum lactate toward normal as early as possible may help improve the chances of survival of these patients in the ICU.