Despite the rapid expansion of living donor liver transplantation (LDLT) in the adult population over the last few years, small-for-size syndrome (SFSS) has emerged as an important clinical problem. We have herein reported a patient who developed clinical evidence of prolonged cholestasis and intractable ascites after a small-for-size right lobe LDLT. The SFSS was attributed to outflow block of segments V and VIII anastomoses with severe portal overperfusion injury. It was successfully treated by reduction of portal pressure and blood flow after trans-splenic arterial ligation. We recommend that trans-splenic artery embolization, a technically simple procedure, be applied to treat portal overperfusion injury in SFSS.