BACKGROUND: Hepatic ischemia-reperfusion (I/R) injury may occur in a variety of clinical settings and this remains a significant problem. Oxygen free radicals, produced on reperfusion have been shown to play a major role in hepatic I/R injury. Various therapeutic effects have been described for Nigella sativa. Additionally, it has been presented that Nigella sativa (orientalis) oil has protective effect against ischemia reperfusion injury to various organs. Therefore, it seems possible that the administration of Nigella sativa (orientalis) oil might protect the liver against the ischemia reperfusion injury . OBJECTIVE: To determine whether Nigella sativa (orientalis) oil prevents hepatic ischemia-reperfusion injury to the liver. METHODS: Thirty-six rats were divided into three groups as control (Group 1), I/R group (Group 2), and Nigella sativa oil (NS) treatment group (Group 3). All rats underwent hepatic ischemia for 60 min followed by 60 min period of reperfusion. Rats were intraperitoneally infused with only 0.9% saline solution in group 2. Rats in group 3 received NS oil (0.2 mL/kg) intraperitoneally, before ischemia and before reperfusion. Blood samples were harvested from the rats, and then the rats were sacrificed. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) levels were determined. RESULTS: The levels of liver enzymes in group 3 were significantly lower than those in the group 2. CONCLUSION: Our results suggest that Nigella sativa oil treatment protects the rat liver against to hepatic ischemia-reperfusion injury.