Abnormal LCTs after surgery are common, and consultants are frequently called on to evaluate critically ill patients with abnormal tests. All patients undergoing consideration for elective surgery and a history of either acute or chronic liver disease require careful presurgical evaluation. A thorough history and physical examination, complete blood count, routine electrolytes, LCTs, and a coagulation profile should be ordered. For patients with marginal hepatic reserve, it is important that patient well-being be maximized before any elective operation. The type of surgery to be performed should also be reviewed. All patients with postoperative jaundice should be evaluated for a history of liver disease. The consultant should also review the surgical procedure performed, anesthetic agents administered, other medications used, and whether blood products were given during the perioperative and postoperative periods. The pattern and timing of LCT abnormalities may also give a clue to the underlying disorder. As in the preoperative assessment, a routine complete blood count,electrolyte panel, LCTs, and coagulation profile should be ordered. Unconjugated hyperbilirubinemia can develop as a consequence of blood transfusions, underlying hemolytic disorders, resorbing hematomas, drug effects, or Gilbert's syndrome. A haptoglobin, reticulocyte count, LDH, and Coomb's test should be considered in patients with unconjugated hyperbilirubinemia. Treatment is directed toward the underlying condition. Conjugated hyperbilirubinemia can occur as a result of either intrahepatic or extrahepatic disorders. Markedly abnormal aminotransferases and LDH in conjunction with a normal abdominal ultrasound scan suggest ischemic liver injury, drug-induced hepatitis, or viral infections of the liver. Treatment entails restoration of hepatic perfusion, removal of offending medications, and supportive care or antiviral agents, respectively. Extrahepatic biliary obstruction must be considered in all patients with conjugated hyperbilirubinemia. Abdominal sonography is the best screening test to assess for obstruction. Patients with common bile duct stones usually require ERCP with sphincterotomy and stone removal. Biliary strictures or leaks may require ERCP with balloon dilation of strictures or stent placement for strictures and leaks; percutaneous drainage of bilomas in combination with broad-spectrum antibiotic agents is recommended for patients with bile leaks and large intra-abdominal fluid collections. Surgery may be required for patients with strictures or leaks not amenable to either endoscopic or percutaneous intervention or for patients who have transected bile ducts after laparoscopic cholecystectomy. Medication effects, benign postoperative jaundice, sepsis, TPN, and acalculous cholecystitis are responsible for intrahepatic cholestasis and conjugated hyperbilirubinemia. Treatment includes removal of offending drugs, supportive care, broad-spectrum antibiotic agents with drainage of infected fluid collections, adjustment of TPN, and either cholecystectomy or cholecystostomy, respectively.