Decompensated liver cirrhosis is the advanced, symptomatic stage of the disease. The occurrence of severe complications, such as ascites formation, gastrointestinal bleeding, hepatic encephalopathy, and jaundice, is the mark of decompensation, and its succession jeopardizes the following course of the disease. In this stage, cirrhosis becomes a systemic disease and is associated with dysfunction up to the failure of extrahepatic organs and systems. The course of decompensation frequently accelerates because of bacterial infections fostering acute disease deterioration and the development of acute-on-chronic liver failure, a potentially reversible but often deadly syndrome characterized by hepatic and extrahepatic organ failure. In these contexts, patients become severely ill and need intensive care to survive the complications and reach liver transplantation if they are potential candidates. This chapter deals with the approach to the most frequent and severe complications of decompensated cirrhosis, such as upper gastrointestinal bleeding, abnormality of the hemostasis, acute renal injury, bacterial infections, sepsis and septic shock, and severe hepatic encephalopathy.