Alagille syndrome (AGS) is an autosomal dominant genetic disorder characterized by chronic cholestasis, congenital heart disease, peculiar facies, butterfly-like vertebrae, and posterior embryotoxon. Liver dysfunction is the common presentation of AGS, and liver transplantation may be indicated. This study examines the outcome of living-related liver transplantation (LRLT) for AGS. Twenty patients with AGS (median age 5.0 years, range 0.6-12.9) underwent LRLT at Kyoto University Hospital between June 1990 and February 2002. Five potential donors were excluded because of paucity of intrahepatic bile ducts diagnosed by preoperative liver biopsy and one because of a hepatic vascular anomaly. The overall 5-year patient survival was 80.4%. Three patients died as the result of the following: complications related to surgery, heart failure caused by progressive pulmonary artery stenosis, and a graft with unsuspected bile duct paucity. Liver dysfunction was improved in all successful cases, and catch-up growth occurred in 90% of patients. LRLT is an efficacious treatment modality for AGS if donors are selected by cautious evaluation to rule out unsuspected bile duct paucity.