Jaundice, with and without hepatobiliary damage, has a wide spectrum of causes. In the initial evaluation, fractionation of the bilirubin facilitates differential diagnosis. Unconjugated hyperbilirubinemia most often is the result of pigment overload or Gilbert's disease. Most patients with jaundice seen by the clinician have underlying hepatobiliary disease. Liver biopsy usually establishes the etiology of hepatocellular forms of jaundice. In patients with cholestasis, visualization of the biliary tree by either transhepatic or endoscopic retrograde cholangiopancreatography provides the most direct means of differentiating mechanical biliary obstruction from intrahepatic cholestasis.