We review information on impaired liver function, focusing on concepts relevant to anesthesia and postoperative recovery. The effects of impaired function are analyzed by systems of the body, with attention to the complications the patient with liver cirrhosis may develop according to type of surgery. Approaches to correcting coagulation disorders in the cirrhotic patient are particularly controversial because an increase in volume may be a factor in bleeding owing to increased portal venous pressure and imbalances in the factors that favor or inhibit coagulation. Perioperative morbidity and mortality correlate closely to Child-Pugh class and the score derived from the model for end-stage liver disease (MELD). Patients in Child class A are at moderate risk and surgery is therefore not contraindicated. Patients in Child class C or with a MELD score over 20, on the other hand, are at high risk and should not undergo elective surgical procedures. Abdominal surgery is generally considered to put patients with impaired liver function at high risk because it causes changes in hepatic blood flow and increases intraoperative bleeding because of high portal venous pressures.