Vascular complications have a detrimental effect on the outcome after liver transplantation. Most studies focus exclusively on hepatic artery thrombosis (HAT). The current study analyzed the incidence, consequences, and risk factors for HAT, portal vein thrombosis (PVT), and venous outflow tract obstruction (VOTO) in a consecutive series of 157 pediatric liver transplantations. The overall incidence of vascular complications was 21%. The incidences of HAT, PVT, and VOTO were 10%, 4%, and 6%, respectively. Patient survival after PVT and VOTO and graft survival after HAT and PVT were less compared with survival of grafts without vascular complications. To identify risk factors for vascular complications, factors related to recipient, donor, and surgical techniques were analyzed. A low donor-recipient (D/R) age ratio, long surgical time, and use of the proper hepatic artery of the recipient for arterial reconstruction were risk factors for HAT. Young age, low weight, segmental grafts, and piggyback technique were risk factors for PVT. Fulminant hepatic failure, high D/R age and weight ratios, and use of segmental grafts were related to VOTO. Vascular complications, which occurred in 21% of the pediatric liver transplantations, had a significant impact on patient and graft survival. Size disparity between donor and recipient was an important risk factor for vascular complications, especially in the case of transplantation of segmental grafts. Patient and graft survival might improve by avoiding the identified risk factors.