To evaluate the therapeutic efficacy of liver transplantation in patients with ATTR Val30Met familial amyloid polyneuropathy (FAP), were repeatedly examined the neurophysiological function of peripheral nerves in nine patients. The maximal motor and sensory conduction velocities (MCV and SCV) of the ulnar and tibial nerves, size of compound muscle action potential (CMAP), terminal latency of CMAP, skin temperature of extremities, CVR-R, blood pressure, heart rate, and Schellong's test were examined before and every 6 months after the operation. Although there were no changes in CVR-R, blood pressure, or heart rate, the skin temperature of foot and hand increased soon after surgery and did not decrease during the period of observation. The temperature-adjusted MCV of tibial nerve gradually increased, but the MCV of ulnar nerve showed no change. The temperature-adjusted tibial nerve SCV worsened slightly soon after transplantation and remained at that level in the distal part. The ulnar nerve SCV worsened and subsequently improved. Liver transplantation is very effective for halting the progression of this type of FAP, but the recovery of peripheral nerve function in patients seems to be very slow and limited, especially the function of large diameter myelinated fibers.