Cadmium (Cd) is a toxic heavy metal and an environmental pollutant. This study aimed to investigate the potential protective effect of Nigella sativa oil (NSO) on Cd-induced liver damage in adult male rats. Forty adult male albino rats were allocated into four equal groups. Group I served as a control. Group II received intraperitoneal injections of 2 mg/kg of cadmium chloride. Group III received NSO 1 ml/kg orally. Group IV were given NSO prior to Cd in the same doses and routes described above. All animals were treated for 8 days, and then were euthanized and their livers were dissected and examined histologically by light and electron microscope. Group II demonstrated hepatic structural injury in the form of dilated central veins with distorted walls, dilated congested sinusoids, pyknotic nuclei, vacuolated cytoplasm, depletion of glycogen granules and lipid droplets, swollen mitochondria, areas of focal hepatic necrosis and infiltration with inflammatory cells. Group IV showed marked improvement of the hepatic damage induced by Cd exposure. Groups I and III showed comparatively normal liver structure with no obvious damage. In conclusion, Nigella sativa oil could be used as a safe and effective plant product to mitigate hepatic insult associated with Cd toxicity.