To study the effect of resveratrol on cerebral infarct volume, cerebral edema as well as the expression of nuclear fac for (NF-kappaB) p65 in the experimental permanent middle cerebral artery occlusion. A middle cerebral artery occlusion model was constructed in 20 Wistar rats with Longa's method. Then the 20 rats were divided into 4 groups: control group, and 3 resveratrol groups (resveratrol of the concentrations of 10(-8) g/kg, 10(-7) g/kg, and 10(-6) g/kg were injected intravenously) (group 1- 4). The area of infarct was examined by 2,3,5-triphenyltetrazolium chloride (TTC) staining. The water content was calculated by dry and wet weight method. The expression of NF-kappaB p65 was investigated with immunohistochemistry. The ischemic volume was 241 +/- 36, 222 +/- 39, 126 +/- 16, and 128 +/- 19 * in the groups 1 - 4 respectively, and the volume ratio was 0.49 +/- 0.04, 0.47 +/- 0.04, 27 +/- 0.02, and 0.43 +/- 0.02 respectively. The brain water content was 83.5% +/- 1.5%, 82.9% +/- 1.4%, 79.5% +/- 1.5%, and 79.9% +/- 1.4% in groups 1 - 4 with a significant difference between 10(-7) g/kg resveratrol group and pure ischemia group and 10(-6) g/kg resveratrol group and pure ischemia group (both P < 0.05). NF-kappaB p65 was not expressed in the normal control group and sham operation group, and was expressed 2 hours after pure ischemia. The expression of NF-kappaB p65 positive cells was the most significant 12 hours after the pure ischemia and began to decrease 24 hours after ischemia. Resveratrol has a neuroprotective effect on the ischemic brain. This effect is related to the inhabitation of expression of NF-kappaB p65.