Folate supplementation is becoming increasingly popular not only to decrease homocystein, a long with the finding that moderate hyperhomocysteinaemia is a cardiovascular risk factor but also diminish some other risks related to folate depletion. The aim of the study was to investigate whether folic acid supplementation leads to behavioural and electrophysiological changes in rats. Therefore, 30 male Wistar rats were divided to three groups. Each of animal groups was consisted of 10 animals. Folic acid was applied to rats by gavage for 8 weeks. Group I as a control group was taking folic acid-free water by gavage throughout the duration of the experiment. Groups II and III were treated with 2.0 mg/kg/day anal 20.0 mg/kg/day of folic acid, respectively. Behavioural effects were evaluated by open field motor activity and by acoustic startle response. Electrophysiological examination was done by recording spontaneous activity and sensory evoked potentials from the visual, somatosensory, as well as auditory cortex. No significant effects on motor activity or acoustic startle response were observed. Both doses of folic acid shortened the latency of the visual cortical evoked potential (p<0.05) and caused a slightly but nonsignificant change in the relative refractory period of a peripheral nerve. There was no effect on the electrocorticograms or on the other evoked potentials. Among the investigated organs, significant differences were observed in relative weight of kidneys and adrenal glands among the folic acid treatment at both the doses and the control groups (p<0.05).