Scarcity of small donors results in a high mortality rate for children on liver transplant waiting lists. To alleviate this problem, we have recently started to reduce the size of livers from older donors to use in children. In the last year, a total of 20 liver transplants were performed in 17 patients, including seven reduced-size liver transplants (RSLT) in six children. Mortality on the waiting list has been reduced to negligible amounts compared with a mortality rate of 25% before starting RSLT in patients with acute liver failure or those whose weight was less than 10 kg. Children undergoing RSLT weighed 10.8 +/- 8.5 kg compared with 20.9 +/- 20.3 for all others (NS). Cold ischemia time was significantly longer in the RSLT group (9.5 +/- 3.0 v 6.0 +/- 2.8 hours, P less than .05) as was intraoperative blood loss (9.4 +/- 9.4 v 3.0 +/- 3.5 blood volumes). There was no significant difference in postoperative aspartate aminotransferase and prothrombin time between the two groups. Four children received a RSLT as a primary procedure and three have survived with good liver function. Two patients were retransplanted with RSLT after a failed first transplant and both died of nonhepatic complications. This compares with 11 of 13 survivors in the whole liver transplant group. Causes of death in children who died after RSLT include cytomegalovirus sepsis (2) and myocardial infarction(1).(ABSTRACT TRUNCATED AT 250 WORDS)