Oxidative stress has been implicated in pathogenesis of various disease events including cancer, cardio vascular diseases, immune system disorders, brain dysfunction and metabolic diseases. The present study aimed to evaluate the protective effect of cinnamon oil on diethylnitrosamine (DENA) and 2-acetylaminoflourene (2-AAF) induced hepatocarcinogenesis. Thirty male albino rats were classified into 3 equal groups. Group (A), rats were kept as control. Group (B), rats received single intraperitoneal injection of DENA (200 mg/kg b.wt.) and 2-AAF (0.03% w/w of diet for 10 successive weeks). Group (C), rats received cinnamon oil 100 mg/kg b.wt. orally via stomach tube daily one week prior to HCC induction (that occurred same way as group B at 2^nd week). Rats were sacrificed at 3 months of the experiment. HCC-induced group (B) showed significant decrease in body mass and significant elevation in liver weight, alpha-fetoprotein (AFP), liver enzymes as well as hepatic malondialdehyde (MDA). In addition to the decrease of Glutathione (GSH) level and superoxide dismutase (SOD) activities. While, HCC rats -pretreated with cinnamon oil in group C, were significantly reversed these destructive actions, with reduced liver toxicity. Histopathologically, the liver of HCC-induced group (B) showed cancer features including hypercellularity, nuclear hyperchromatia and miototic figures. HCC rats pretreated with cinnamon oil revealed partial reversal to the normal liver architecture. The present findings proposed that, this natural oil has the ability to improve liver function, significantly reduced the liver toxicity and HCC development. However, further investigations are needed before wide scale recommendation.