This study aimed to determine whether chronic occupational exposure to pesticides causes neurophysiologic abnormalities in farmers. The nerve conduction study and questionnaire measured 31 male farmers and 15 male reference subjects living in the same area. Regression analysis was used to evaluate the relationships between pesticide use and nerve conduction study after adjustment for potential confounders. Sensory nerve conduction velocities on median and ulnar nerves;, and motor nerve conduction velocities on posterior tibial and peroneal nerves in farmers were significantly slower than their respective controls. Multiple regression models showed significant exposure-response relationship with pesticide exposure days and median, posterior tibial nerves conduction velocities. Occupational exposure to pesticides is associated with impaired peripheral neurophysiologic function in farmers.