We report two cases of unusual repeated hypotension, decreased cardiac output, decreased mixed venous oxygen saturation, decreased central venous pressure, pulmonary artery pressure, and pulmonary wedge pressure after the completion of all vascular anastamoses of liver transplantation. These unstable hemodynamics appear to reflect a clinically relevant picture of hypovolemia. However, the real cause was partial hepatic outflow obstruction. The obstruction was suspected because hypotension was alleviated by elevating the full-sized liver graft ventrally and to the left. Doppler ultrasound examination confirmed that the flow velocity of the hepatic vein outflow was insufficient when the liver fell to its resting position in the right hepatic fossa. An additional side-to-side cavo-caval anastomosis resolved the problem in one patient, whereas the other required not only the additional anastomosis, but also application of a tissue expander filled with 770 mL normal saline beneath the liver to eliminate the obstruction. We emphasize that obstruction of the hepatic outflow causes only temporal hypovolemia because of a decrease of venous return and that treatment of this complication should be surgical intervention to relieve the obstruction. Blind resuscitation with fluids will not solve the problem and, in fact, may result in fluid overload with subsequent complications.