Many surgical procedures, such as limb revascularization and free-flap reconstruction, involve prolonged ischemia of skeletal muscle. Ischemic damage can lead to severe postoperative complications, including muscle dysfunction and necrosis. In order to prevent these complications of ischemia reperfusion injury, various free radical scavengers and methods have been tested experimentally. Either ischemic preconditioning or N-acetylcysteine alone attenuated these changes. This study, examined the effects of ischemic preconditioning in combination of N-acetylcysteine on skeletal muscle ischemia reperfusion injuries. Twenty four wistar male rats were divided randomly into four experimental groups: group A (ischemia reperfusion), group B (ischemia reperfusion + N-acetylcysteine), group C (ischemic preconditioning) and group D (ischemic preconditioning + N-acetylcysteine). After intramuscular ketamine and xylazine anesthesia, femoral artery was exposed. Animals in groups A and B were undergone 2h of ischemia by occlusion femoral artery and 24h of reperfusion and rats in groups C and D were undergone two 20- min cycles of ischemic preconditioning followed by 2h ischemia and 24h reperfusion. Rats that were treated with Nacetylcysteine (groups B and D) given IV at a dose of 150 mg/kg, immediately before reperfusion. After 24h of reperfusion, rats were euthanized and left gastrocnemius muscle harvested for histopathological analysis under optical microscopy. Inflammatory changes, neutrophil presence, interstitial edema, hemorrhage and necrotic fibers in the muscle were scored. The extent of muscle changes in the group D was significantly lower than other groups (p<0.05). Degree of muscle changes in B and C groups were lower than that in the A group (p<0.05). These results suggest that ischemic preconditioning and N-acetylcysteine act synergistically to protect skeletal muscle against ischemia reperfusion injuries.