Biliary tract complications are reported in 15% to 30% of orthotopic liver transplantations (OLTs). Since 1986, 53 OLTs were done in 48 children with a mean age and weight of 5.3 years and 18.9 kg, respectively. Twenty-seven transplantations (51%) were reduced liver grafts (RLG) and 26 (49%) were whole liver grafts (WLG). Since 1988, 70% of transplantations have been RLG. Choledochocholedochostomy (mean weight, 25 kg) with a T-tube (CC) or choledochojejunostomy (CJ) (mean weight, 14.5 kg) were done in 24 (45%) and 29 (55%) cases, respectively. The overall mortality was 19% but none of the deaths were related to biliary problems. There were 13 biliary tract complications (24.5%) in 11 patients including 7 leaks, 5 obstructions, and 1 intrahepatic biloma. Leaks leading to bile peritonitis were managed with simple suture and drainage and were related to the T-tube (4), to the Roux-en-Y loop (2), and to the transection margin of a RLG (1). Obstruction was documented in 5 cases with none associated with hepatic artery thrombosis (HAT). Stenosis after CC reconstruction (2) required conversion to CJ. Two patients had revision of CJ because of kinking of the common bile duct after a left lateral segment graft and an anastomotic stricture 46 months after OLT. The last patient developed a vanishing bile duct syndrome 4 months posttransplant and is awaiting retransplantation. One patient had multiple episodes of cholangitis after HAT and was retransplanted. Neither the type of grafts (RLG 25.9% v WLG 23.1%) nor the type of biliary reconstruction (CC 25% v CJ 24%) influenced the rate of biliary complications.(ABSTRACT TRUNCATED AT 250 WORDS)