Tongxinluo has been widely used in China for the treatment of acute stroke and for neu-roprotection. However, there are few positron emission tomography (PET) studies on the neuroprotective effect ofTongxinluo on cerebral ischemia/reperfusion in small animals. In the present study,Tongxinluosuperfine powder suspension or its vehicle was administered intragastrically to rats for 5 successive days before middle cerebral artery occlusion.18F-lfuo-rodeoxyglucose (FDG) small animal PET imaging showed that at 1 and 2 weeks after cerebral ischemia/reperfusion, glucose metabolism in the ischemic area was greater in rats that had receivedTongxinluo than in those that had received the vehicle. Nissl staining showed that 2 weeks after cerebral ischemia/reperfusion, there was less neuronal loss in the prefrontal cortex in Tongxinluo-treated rats than in controls. In addition,Tongxinluo-treated animals showed better neurologic function and lower cerebral infarct volume than rats that received the vehicle. These findings suggest thatTongxinluo exhibits neuroprotective effects in cerebral ischemia/reper-fusion injury and demonstrates that18F-FDG small animal PET imaging is a useful tool with which to study the molecular pharmacology of traditional Chinese medicine.