Familial amyloid polyneuropathy (FAP), which is a fatal disorder inherited in an autosomal dominant fashion, is characterized by systemic accumulation of polymerized transthyretin (TTR) in the peripheral nerves and systemic organs. Liver transplantation has become an accepted treatment of this disorder because it stops the major production of amyloidogenic TTR. However, improved survival of transplant patients compared with that of nontransplant patients has not been sufficiently demonstrated. This study investigated whether transplantation improved the long-term outcome of patients by comparing the survival of patients who had transplantations with that of patients who had not had transplantations. Eighty consecutive patients with FAP Val30Met who visited Kumamoto University Hospital between January 1990 and December 2010 were studied. The transplant group consisted of 37 patients who had a partial hepatic graft via living donor transplantation in Japan or who underwent liver transplantation in Sweden, Australia, or the United States. The nontransplant group consisted of 43 patients with FAP. Survival was evaluated by using Kaplan-Meier analysis, and the difference in survival was examined via the log-rank test. The transplant group had prolonged survival (p < 0.001) compared with the nontransplant group. The estimated probability of survival at 10 years was 56.1% for the nontransplant group vs 100% for the transplant group. Liver transplantation should be considered as an effective treatment in clinical management of patients with FAP Val30Met. This study provides Class III evidence that liver transplantation prolongs survival in patients with FAP Val30Met.