BACKGROUND: Recently, liver transplantation has been used to treat patients with familial amyloid polyneuropathy (FAP). OBJECTIVE: To describe the clinical course of patients with FAP who received partial-liver transplantation from living donors. DESIGN: Case series. SETTING: University hospital in Matsumoto, Japan. PATIENTS: 11 patients with FAP who underwent partial-liver transplantation. The transthyretin gene abnormality in all 11 patients was the substitution of methionine for valine at position 30. INTERVENTION: Partial liver transplantation from living donors. MEASUREMENTS: Preoperative and follow-up (3 to 64 months) clinical data, including routine laboratory data, nerve conduction velocity tests, and sural nerve histology. RESULTS: All 7 patients who had severe gastrointestinal autonomic disorders or polyneuropathy localized to the lower limbs for less than 4 years showed improvement. Three of 4 patients with polyneuropathy involving both the upper and lower limbs had adverse outcomes, including two deaths. The preoperative duration of their illness was more than 6 years. These 3 patients also had marked decreases in creatinine clearance and nerve conduction velocities and severe loss of myelinated fibers in sural nerves. CONCLUSION: Preoperative clinical severity and duration of illness are associated with outcomes after liver transplantation for FAP.