Hyperlipidemia is one of the major health concerns worldwide. The present study aimed at utilizing clinicopathological tools to investigate the possible improving effect of Avena sativa mucilaginous extract (ASE) on lipid metabolic and liver function profiles in albino rats. The rats were rendered hyperlipidemic by 6-week supplementation of high-fat diet ad libitum. The rats were grouped into seven groups; with different treatment applications. Rats of group-I received normal diet and served as normal control; those of group-II were kept on high-fat (cholesterol 1% + coconut oil 2%) diet for 6 weeks and served as diseased control. Rats in group-III were kept on high-fat diet and received ezetimibe (1 mg/Kg B. Wt, orally, daily) and served as standard. Those in group-IV and V were kept on high-fat diet and received ASE at doses of 25 and 50 mg/Kg B. Wt., orally, daily (small and high doses, SD and HD, respectively) and served as treated-SD and treated-HD, respectively. While the last two groups (VI and VII) were kept on normal diet and received SD and HD of ASE. Blood samples for serum were taken for clinicochemical analysis on days 28 (4 weeks) and 42 (6 weeks) of the experiment and tissue specimens were taken for histopathology. ASE significantly (P