Hepatopulmonary syndrome (HPS) is a progressive, debilitating complication of end-stage liver disease. In contrast to the well-established reversal of HPS after deceased donor liver transplantation (DDLT), little has been written about the natural course of HPS after the newer procedure of living donor liver transplantation (LDLT). We describe HPS in a small series of 4 liver transplant recipients (2 DDLT; 2 LDLT) at a single center. Before transplantation, these 4 patients had a mean shunt fraction of 23.6 +/- 14.3% and a mean PaO2 of 58.5 +/- 11.3 mm Hg. All 4 patients used supplemental oxygen before transplantation. Sixteen weeks after transplantation, all 4 patients had normalized or improved shunt fraction and PaO2. These patients regained normal pulmonary function within a few months, despite the period of hepatic regeneration after LDLT. In conclusion, both DDLT and LDLT are associated with rapid and dramatic reversal of HPS.