Tau-Vinyl GABA (vigabatrin, GVG) is a novel antiepileptic drug that irreversibly inhibits GABA transaminase and elevates GABA levels in all parts of the brain. In the present study, we investigated the anxiolytic and behavioral effects of GVG in the elevated plus-maze and the hole board compared to diazepam. Doses of 500 and 1,000 mg/kg GVG were injected IP to different groups of male Wistar rats and animals were tested either 4 or 24 h after injection. Animals administered diazepam (1.5 mg/kg, IP) and saline (I ml) were tested 20 min after injection. GVG and diazepam were found to decrease significantly the number of squares visited and rearing; both had a suppressant effect on locomotor activity. Neither drug had an effect on exploration (head dipping). GVG at a dose of 1,000 mg/kg was shown to have a similar anxiolytic activity either after 4 or 24 h as diazepam, while GVG at 500 mg/kg did not show any significant anxiolytic effect.