Hypercholesterolemia is one of the major risk factors that precipitate coronary heart disease, atherosclerosis, peripheral vascular and ischemic cerebrovascular diseases. Protective effects of flaxseed oil on hepatic oxidative stress and antioxidant status, liver and cardiac marker enzymes in addition to pro-inflammatory cytokines in hypercholesterolemia-induced in rats were evaluated. Forty male rats were divided into four equal groups. Group Ι :(Control) rats were fed on normal diet. Group Π: hypercholesterolemic diet (HCD) rats were fed [4% cholesterol (w/w) and 1% cholic acid]. Group III: rats were fed HCD and received flaxseed oil (270 mg/kg b.wt/day, orally). Group IV: rats were fed normal diet and administer flaxseed oil (270 mg/kg b.wt/day, orally). Blood and liver tissue samples were collected at 2, 4 and 6 weeks from the onset of treatment with flaxseed oil. The obtained results showed marked increase in serum tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), LDH, CK-MB, ALT, AST and GGT activities in addition to liver nitric oxide (NO) and L-MDA levels in hypercholesterolemic rats. Meanwhile, liver CAT, SOD and GPx activities were significantly decreased. Treatment with flaxseed oil in hypercholesterolemic rats lowered serum TNF-α, IL-6, liver marker enzymes, NO and L-MDA and ameliorate antioxidant enzymatic status in liver tissue. These results suggest that, flaxseed oil may be effective in controlling cholesterolemic status and has the potential in reducing cardiovascular complications due to hypercholesterolemia. Also, administration of flaxseed oil enhanced the antioxidant defense system in liver tissues and have a meliorating effect in hypercholesterolemia induced hepatic oxidative stress.