Leukotriene C4 (LTC4) and prostaglandin E2 (PGE2) are known to be highly potent cerebral vasoconstrictors which are formed from arachidonic acid (AA). They enhance vascular permeability, inducing vasogenic edema that may damage the ischemic penumbra after ischemia and reperfusion. The inhibitory effect of aqueous garlic extract (AGE) on AA metabolism in human platelets is known. In this study, following the global ischemic model application to the rats, all underwent 10 min ischemia and were reperfused for different periods. The levels of LTC4 and PGE2 in rat forebrain were then measured. One rat group consisted of 8 rats. In the combined reperfused groups both metabolites increased significantly when compared with the 10 min ischemia alone, no reperfusion group (p < 0.05). In the 8 min reperfused group, PGE2 and LTC4 levels increased significantly at 60 min of reperfusion compared with each corresponding control group (P < 0.005). PGE2 and LTC4 levels were reduced significantly at 60 min of reperfusion compared with the 8 min reperfused group (P < 0.005). AGE (1 ml/kg) reduced both LTC4 and PGE2 levels significantly in the 8 min and 60 min reperfused group (P < 0.001, P < 0.001, P < 0.05, P < 0.01). In conclusion, AGE reduced LTC4 and PGE2 levels at a dosage of 1 ml/kg following 8 and 60 min reperfusion. It may be helpful in reducing AA metabolite levels and preventing injury after ischemic phenomena.