Hypercholesterolemia is one of the most important risk factors for atherosclerosis and subsequent cardiovascular disease. In the present study, the therapeutic effect of chitosan administration on serum lipids profile, apolipoprotein A (apo A) and apolipoprotein B (apo B) in addition to Lipid composition in erythrocytes membrane [Total cholesterol (TC), and free fatty acids (FFA)] in hypercholesterolemia induced in rats have been evaluated. Sixty male rats were divided into four equal groups of 15 rats each. Group Ι (Control group): rats fed on normal diet. Group Π: Rats fed on high cholesterol diet (HCD) [4% cholesterol (w/w) and 1% cholic acid]. Group III: Rats fed with HCD + Chitosan 5% (5g/100g/day) after two weeks from the onset of the experiment (induction of hypercholesterolemia). Group IV: Rats fed with normal diet + Chitosan5% (5g/100g/day). Blood samples were collected from all animal groups three times at 2, 4 and 6 weeks from the onset of treatment with chitosan. The obtained results showed a marked increase in serum total cholesterol, triacylglycerols, LDL-C, VLDL-C, phospholipids and Apo B concentration as well as in erythrocytes membrane lipids composition (TC and FFA) in hypercholesterolemia induced in rats. However, serum HDL–C and Apo A levels were significantly decreased. Treatment with chitosan to hypercholesterolemic induced rats lowered serum lipids and lipoproteins profile (LDL-C, VLDL-C), and erythrocytes lipids composition with increasing HDL-C and Apo A concentrations. These results suggest that, chitosan may be effective in controlling cholesterolemic status and improving dyslipidemia and has the potential in reducing cardiovascular complications due to hypercholesterolemia.