Reduced-organ liver transplantation for children is effective in lowering pretransplantation morbidity and mortality. Improvements in surgical technique have reduced vascular complications; however, biliary complications continue to account for significant posttransplantation morbidity. This investigation chronicles the incidence and type of biliary complications encountered with reduced-organ liver transplantation. Retrospective review of reduced-organ liver recipients over a 59-month period was performed, and biliary complications were classified as (1) missed biliary radicle, (2) anastomotic leak requiring revision, and (3) biliary stricture. From July 1992 to May 1997, 42 children received reduced-organ grafts: 32 living-donor, 8 cadaveric-reduced, 1 split-liver, and 1 auxiliary orthotopic liver transplant. Of the 42 grafts, 41 were Couinaud segments II/III and 1 was segments II/III/IV. Ten biliary complications were identified in 9 recipients (24%). Biliary complications included parenchymal radicle leaks, 5 (50%); biliary strictures, 3 (30%); and anastomotic leaks, 2 (20%). Although technical advances have reduced the incidence of biliary complications secondary to organ ischemia, parenchymal radicle leaks continue to be a source of morbidity for reduced-organ recipients. Planned exploration on posttransplantation day 7 was performed on the most recent 26 of the 42 total reduced-organ procedures as a mechanism to identify and treat early technical complications. Planned exploration as a routine component of reduced-organ transplantation has yielded a 15% incidence of discovered parenchymal leaks and a 5% incidence of discovered anastomotic leaks. This series underscores the necessity for improved anatomical studies to correctly identify duct territories and the development of accurate noninvasive methods to assess the biliary system preoperatively and intraoperatively in the application of reduced-organ liver transplantation.