Objective: To compare the effect of 1-year hemodialysis and on-line hemodiafiltration treatment on peripheral neuropathy. Patients and methods: 99 chronic dialysis patients were assigned randomly to on-line HDF group and HD group. 31 patients of on-line HDF group received regular hemodialysis and on-line HDF once per two weeks, while 68 remaining patients received hemodialysis trice a week and were considered as a control group. Nerve conduction studies of peroneal, tibial, sural, ulnar and median nerves were perfomed in each group and paired comparision of electroneurographic parameters were done after 6 month and 12 month treatment. Results: After the 1-year treatment,electroneurographic indicies showed significant improvement in the on- line HDF group. The sensory and motor nerve conduction velocities, the action potential amplitudes of peripheral nerves in on-line hemodiafiltration group increased, while the distal latencies decreased significantly in comparision with that in hemodialysis group. Conclusion: The present study suggests that on line hemodiafiltration might improve electrneurographic parameters in patients with chronic renal failure treated with hemodialysis.