Blood flow to the liver is maintained by hepatic arterial buffer response (HABR), which is an essential autoregulatory mechanism. Portal hyperperfusion impairs hepatic artery flow (HAF) due to the HABR, probably resulting in high incidence of biliary and artery complications in liver transplantation. The previous studies have reported that portal vein flow is directly correlated to the splenic volume. The aim of this study is to investigate the impact of preoperative splenomegaly, and assess the efficacy of portal modulation such as preoperative splenic artery embolization (SAE) or intraoperative splenic artery ligation (SAL) on biliary and artery complications after living donor liver transplantation (LDLT). From 2004 to 2011, 160 consecutive LDLT were retrospectively analyzed. Patients were divided into group 1 with splenomegaly (n= 128) and group 2 without splenomegaly (n=32). The overall biliary and artery complication rate was 43% (n=68) and 11% (n=17) respectively. The biliary complication rate was 48% (n=61) in group 1 and 22% (n=7) in group 2 (P=0.008). Biliary anastomotic stricture was seen in 54 patients(42%) in group 1, and 7 patients(22%) in group 2 (P=0.034), whereas biliary non anastomotic stricture was seen in 4 patients(3%) in group 1, and 0 patient in group 2 (P=0.311). 27 patients(20%) in group 1 and one patient(3%) in group 2 had early biliary stricture (≤90 days after LDLT) (P=0.024), on the other side, 33 patients(26%) in group 1 and six patients(19%) had late biliary stricture (>90 days after LDLT) (P=0.41). The artery complication rate was 13% in group 1 and 0% in group 2 (P=0.03). Hepatic arterial thrombosis (HAT) occurred in three (18%), and hepatic arterial stenosis (HAS) in four (23%), and splenic artery syndrome (SAS) in 10 patients (59%) each. The incidence of biliary complication, especially early biliary anastomotic stricture in group 1 was greater than in group 2. Similarly the incidence of artery complication was greater in group 1, and SAS was the most common artery complication in group 1. In a multivariate analysis, preoperative splenomegaly was an independent risk factor for both biliary and artery complications in LDLT. Of the 160 LDLT recipients, portal modulation such as preoperative SAE or intraoperative SAL was performed in 81. There was no significant difference in the incidence of biliary and artery complications between the patients who underwent portal modulation and those who didn‘t undergo portal modulation despite the rate of patients with splenomegaly was significantly higher in the patients who underwent portal modulation. In conclusion, preoperative splenomegaly is important to predict the risk of biliary and artery complication after LDLT. Recipient with Splenomegaly may have impaired HAF due to the HABR, resulting in high incidence of biliary and artery complications after liver transplantation. Portal modulation through preoperative SAE or intraoperative SAL may be effective in prevention of biliary and artery complications after LDLT through a decrease in portal hyperperfusion.