The purpose of this study was to investigate the effect of mild chronic exercise on visual evoked potentials (VEPs). Twenty male Wistar rats were randomly divided into two groups: Control (C) and Exercise (E) groups. Exercise was performed on a motor-driven treadmill for 8 weeks. After 5 min of exercise, plasma lactic acid levels were determined. At the end of the experimental period, VEPs were recorded from E group twice: Five min (E-5 min) and 24 h (E-24 h) after the last bout of exercise. During visual evoked potential (VEP) recordings body temperature of the animals was kept constant to eliminate the effect of temperature changes. No difference was found between the lactic acid levels of two groups. The mean latencies of VEPs from E-5 min were shortened compared with the control group. The mean latencies of VEP components in E-24 h were observed to have returned to the control levels. Peak to peak amplitudes of VEPs were found to be unaltered among all measurements. We concluded that immediately after exercise, VEPs latencies were shortened independently from body temperature via unknown mechanisms. The latencies of VEPs were returned to control values after 24 h.