Background Only a few reviews of small case series and individual case reports including a relatively small number of adult patients undergoing liver transplantation for hepatopulmonary syndrome(HPS)are available,and there has been no prospective evaluation of the long-term outcome of HPS patients after orthotopic liver transplantation(OLT).The aim of this study was to determine the frequency of HPS in OLT patients with chronic end-stage liver-disease,and the short-term and long-term postoperative outcome of HPS patients after OLT.Methods This prospective study included 31 HPS and 30 control,non-HPS patients.The preoperative conditions were similar between the two groups.Twenty-six of 31 HPS patients and all of the non-HPS patients underwent OLT.Standardized methods,such as arterial blood gas at room air and 99m-technetium macroaggregated albumin (~(99m)Tc MAA)lung and brain perfusion scanning were performed for the diagnosis of HPS.Patients were followed after OLT.Results The incidence of HPS in OLT patients was 9.3%(26/279).Hypoxemia in HPS was obviously improved with a normalized shunt of ~(99m)Tc MAA in the lungs after OLT.The immediate postoperative survival rate(within 28 days after OLT)of HPS was 76.9%(20/26).The one year survival was 61.5%(16/26)and four-year survival was 57.7%(15/26);much higher than HPS patients without OLT(0).But high postoperative morbidity and mortality were observed in HPS patients whose death occurred within 3 months of OLT due to complications summarized in this study.Conclusions Liver transplantation was an effective treatment for HPS.But the postoperative mortality rate following OLT in HPS patients was still much higher than that of patients without HPS.