Urinary Tyrosine Inhibitor (UTI) is produced in the liver and excreted in urine hepatic inflammation, infection or malignancy. We assess the possible implications of UTI in biliary atresia (BA). Liver function was used to divide 34 postoperative BA patients into 2 groups: Group 1 (n=25), anicteric (total bilirubin [T-Bil] <2.0 mg/dl); and Group 2 (n = 9), icteric (total bilirubin >2.0 mg/dl) with abnormal liver function test results, and repeated episodes of cholangitis. 26 age-matched subjects with no history of liver disease acted as controls