Intractable ascites after orthotopic liver transplantation (OLT) is a relatively rare complication. However, it often takes a life threatening course, which requires re-transplantation. In previous studies, several reports gave hepatic sinusoidal obstruction syndrome (SOS) as one of the causes of refractory ascites. However, the detailed etiology of SOS after OLT and its association with clinical consequences remain unclear because there have been few studies to date. We report two recent cases with rapidly progressive refractory ascites associated with SOS, following completely different clinical courses. In case 1, the first episode of acute allograft rejection triggered SOS and subsequent intractable ascites, while the second acute rejection worsened his clinical status. A transjugular intrahepatic portosystemic stent-shunt (TIPS) was placed and this procedure resulted in complete disappearance of ascites and of renal dysfunction. In contrast, refractory ascites in case 2, who had neither rejection nor mechanical outlet obstruction, worsened despite TIPS stent placement, and re-transplantation was necessary. We speculate that the pre-existing diseased liver of the cadaver donor caused this serious complication, necessitating a second graft.