Acute-on-chronic liver failure (ACLF) represents a reversible syndrome associated with high short-term mortality, characterized by acute decompensation in patients with chronic liver disease and extrahepatic organ failure. Diagnosis and prognosis assessment is based on a newly developed diagnostic score, the Chronic Liver Failure Consortium Organ Failure score. Susceptibility to infections and systemic inflammation are typical triggers. The authors report a case in which a patient with alcohol-related cirrhosis was admitted to the hospital with acute decompensation and developed ACLF during hospitalization. This case led to an evaluation of the underlying process causing ACLF: infection versus acute alcoholic hepatitis.