The division of a single hepatic allograft to create two reduced-size grafts has been reported with decreased graft survival (50%) resulting in decreased enthusiasm for this approach. The authors reviewed their experience with 12 recipients of this procedure to evaluate the outcome of the children electively undergoing transplant with the "leftover liver." A retrospective review of six pairs of children receiving part of one hepatic allograft included donor anatomy, recipient operation, and allograft and patient outcomes. Recipient pairs were selected according to blood type compatibility, medical priority, and size restrictions of the larger right lobe and the smaller left lateral segment. Patient and graft survival were compared with elective and urgent patients undergoing whole or reduced-size transplants. Six donors weighed 71.8 +/- 17.4 kg and were 22.6 +/- 11.0 years of age. Recipients of the right lobe were 11.8 +/- 4.2 years of age and weighed 41.9 +/- 14 kg. Recipients of the left lateral segment were 1.81 +/- 1.1 years of age and weighed 9.85 +/- 1.82 kg. Six patients were initially offered the donor allograft because of their hospitalization, critical illness or waiting time. Six additional patients electively underwent transplantation with the leftover liver. Donor organs were screened for normal arterial anatomy. Division of the allograft was performed on the back table in the falciform groove. Generally the left lateral segment graft received the major portion of the hepatic artery and the right lobe the major portion of the portal vein. Five of six (83%) elective patients, two receiving the right lobe and three receiving the left lateral segment had prompt recovery and left the hospital without surgical complication. One recipient of a right lobe transplant died from primary allograft nonfunction. These results are not different from the outcomes of all elective patients who underwent transplantation with whole or reduced-sized transplants in the same program. The authors conclude that split liver transplantation benefits the stable patient who electively receives the liver leftover after reducing the size of a large donor liver for a critically ill child.