BACKGROUND: Transient global cerebral ischemia can cause selective hippocampal lesion and spatial learning impairment. To evaluate whether some commonly used laboratory animal anesthetics, pentobarbital, ketamine and xylazine, can affect ischemic brain injury, the effects of the anesthetics on Morris water maze task following transient global ischemia were investigated in Mongolian gerbils. METHODS: The ischemia was induced by bilateral carotid artery occlusion for 2 or 5 min. Morris water maze task was started 3 days later and performed for 15 days. RESULTS: Every animal acquired Morris water maze task as trial proceeded and there was no difference in the latency time on the last (15th) trial. However the ischemic groups (2 min and 5min) showed delayed acquisition of a Morris water maze task and the longer the ischemic time was the more the acquisition delayed. There were no differences in the acquisition of the maze task among pentobarbital-, ketamine- and ketamine/xylazine-anesthesia in either sham- or 2 min-ischemic group, but ketamine/ xylazine anesthesia significantly reduced the acquisition delay in 5 min-ischemic group compared with pentobarbital- or ketamine-anesthesia. CONCLUSIONS: These results suggest that ketamine/xylazine anesthesia have more neuroprotective effect on ischemia-induced brain injury, compared with pentobarbital- or ketamine-anesthesia, in gerbil global ischemia.