Emamectin benzoate (EMB) is an avermectin insecticide used extensively in pest control on vegetable and field crops. In the current study, we evaluated the hepatotoxicity of EMB on male rats and the possible ameliorative role of Nigella Sativa oil (NSO). Rats (Thirty-five) were randomly divided into 5 equal groups. Control group the rats were treated orally with distilled water, NSO group; the rats received NSO at a dose of 3 ml kg-1 B.W orally day after day for 6 weeks by stomach tube, EMB group; the rats received EMB at a dose of 9 mg kg-1 orally day after day for 6 weeks by stomach tube; EMB+ NSO group; the rats received EMB and NSO day after day for 6 weeks; EMB then NSO group; the rats received EMB orally day after day for 4weeks alone then received NSO day after day for 2 weeks. Intoxication of rats with EMB significantly showed that EMB treatment resulted in a decrease in the body weight in compared with the control group. Regarding to the histopathological examination, EMB treatment induced coagulative necrosis and blood vessels congestion of the liver in treated rats. Furthermore, it resulted in sporadic cell necrosis in individual hepatocytes, central vein and blood sinusoids revealed dilatation and congestion. Portal areas revealed moderate fibrosis with few mononuclear inflammatory cells infiltration and hyperplasia of bile duct lining epithelium. Hemorrhage and hemosiderosis in liver parenchyma. The co-administration of NSO with EMB modulated the EMB induced alterations in body weight and liver structure.