Changes in brain temperature during and following ischemia have not been systematically examined in the gerbil. In this study, gerbils were subjected to a 5-min bilateral carotid artery occlusion. During surgery, skull and body temperatures were maintained with a heated water blanket and a homeothermic blanket unit, respectively. Rectal, skull and brain temperatures were monitored throughout ischemia and for up to 3 h in the post-ischemic period. Intra-ischemic brain temperature fell by approximately 1.5-degrees-C even though skull and rectal temperatures remained at normal values. Since brain temperature modulates the extent of ischemic injury it may not be sufficient to rely on skull and/or rectal temperature readings, especially during periods of anesthesia.