To analyze the risk factors in the development of hepatic artery thrombosis (HAT) and assess the impact of our perioperative management for HAT on the long-term outcome after pediatric living donor liver transplantation (LDLT), we reviewed 382 patients under 12 yr of age who underwent 403 LDLT from January 1996 to December 2005. One- and 10-yr patient survival rates were 78% and 78% in the patients with HAT (27 patients; 6.7%), and 84% and 76% in the patients without HAT, respectively (p = n.s.). Univariate analysis showed gender (female), body weight (lower), and graft-to-recipient weight ratio (higher) were significant risk factors in the patients with HAT (p < 0.05). Patients with Doppler ultrasound signal loss of the hepatic artery (HA) accompanied by an increase of liver enzymes underwent thrombectomy and reanastomosis (S-group, n = 13), and patients with a weak HA signal underwent anticoagulant therapy (M-group, n = 13). One patient underwent re-LDLT. One- and five-yr patient survival rates were 83% and 83% in the S-group, and 77% and 77% in the M-group (p = n.s.). The incidence of biliary complications in the S-group (58%) was significantly higher than that of the M-group (15%). For a successful long-term outcome, the early detection of HAT and prompt medical and surgical intervention are crucial to minimize the insult of HAT.