A 60-yr-old man having hepatitis C virus-associated liver cirrhosis and hepatocellular carcinoma underwent living donor liver transplantation using a left liver graft. On post-operative day 20, the patient developed a large amount of ascites and hypovolemic shock because of decreased venous return. Emergency laparotomy revealed that fixation of the round ligament to the abdominal wall was loose, and free movement of the graft into the right subphrenic space had caused twisting the hepatic vein. After upward traction of the round ligament, two Foley balloon catheters were inserted into the right subphrenic space to maintain the graft in the midline portion. The catheters with the balloons were removed on day 30 after re-operation. This method is easy, simple and inexpensive for the treatment of hepatic venous outflow block after partial liver transplantation.