Abstract: The nutritional analysis of raw, ground Oat grain was conducted according to AOAC, 2005. The mean percentage value of various nutrients in Oat was following, protein (12.32%), fat (4.49%), crude fiber (6.06%), ash (3.04%) and moisture 10.01%. The lignin and cellulose content were also assessed; cellulose content being estimated as (4.11%) and lignin as (2.69%). High fiber diet (HFD) for rats was prepared using dietary fiber isolated from raw ground seeds, with some necessary alteration of the basic purified diet AIN-76 (BPD AIN-76) for rats. The rats (n = 36) were equally divided into six groups to study the effect of Oat HFD on serum glucose and serum total cholesterol (TC). Group I comprised on rats with normal blood glucose level fed on basal diet (AIN-76), Group II was Alloxan (ALX monohydrate) induced diabetic rats fed on basic purified diet AIN-76. Group III comprised of diabetic rats fed on Oat HFD. The same research design was replicated to study the cholesterol level, hence Group IV comprised normal rats on BPD AIN-76, Group V was of induced Hypercholesterolemic rats on BPD AIN-76 and Group VI consisted of induced hypercholesterolemic rats on Oat HFD. The random blood glucose level (RBGL) (mg/dL) and TC (total cholesterol) level (mg/dL) were monitored for a period of six weeks. It was observed that Oat had a significant effect on the lowering of RBS level and total cholesterol in the experimental animals.