Alagille syndrome (ALGS) is an autosomal dominant disorder characterized by genetic abnormalities of Jag1 and the Notch signaling pathway. It is histologically characterized by paucity of intrahepatic bile ducts leading to chronic cholestasis. Laboratory findings are often remarkable for serum bilirubin values up to 30 times the normal and serum bile salts up to 100 times the normal. In addition to liver disease, Alagille syndrome is associated with cardiac disease, skeletal and ocular anomalies, and characteristic facies. Alagille syndrome is a well-known, clinically important, but infrequent disease, most discovered by chance. It is a cause of cholestasis among children and adolescent anatomically, awareness of this congenital anomaly is important for the diagnosis and therapy. Rare cases of Alagille syndrome have been reported in the literature. We herein describe a case of Alagille syndrome in 20-year-old woman. The diagnosis of Alagille syndrome was made on the basis of combination of genetic testing for Jag 1 mutation, liver biopsy confirming paucity of interlobular bile ducts and characteristic clinical findings.