Our previous study has demonstrated that sodium selenite prevents oxidative stress, suggesting that selenium can improve diabetic peripheral neuropathy. Results from this study demonstrated that diabetes mellitus resulted in significant increased time to peak, as well as rheobase and chronaxie values. In addition, maximum depolarization, area under compound action potential, kinetics, and conduction velocities of fast and slow nerve fiber groups were decreased. Sodium selenite exhibited positive effects on alterations of diabetes mellitus-induced conduction velocity distribution. This neuroprotective effect was primarily observed in the area under compound action potential and compound action potential kinetic waveforms, as well as rheobase and chronaxie. Results from this study showed that selenium supplementation blocked the diabetes mellitus-induced shift of actively contributing nerve fibers, and restored levels towards age-matched control group values. Chronic selenate supplementation for experimental diabetic peripheral neuropathy exhibited protective effects in measured electrophysiological parameters.