Eight groups of rats which represent eight treatments were fed on yellow corn grains infected with a sore suspension of A. flavus (2500-3000 sores/g. grains). Weight of rats was significantly reduced in all groups contained diets contaminated with aflatoxins, spores or both of them when compared with the control (non¬infested). The reduction in weight of rats was increased by increasing concentration of the aflatoxins. Also, the rats fed on diets contained high concentration of aflatoxins showed some clinical changes such as falling of their body hair. Some alteration in liver as, severe congestion (hyperaemia) of the central vein, sinusoides, and degenerative changes in the form of vascular and hydropic degeneration were show in the groups fed on diets containing different concentration of aflatoxins (B1 and/or B2) and/or spores of A. flavus. Significantly reduced count of red blood cells (RBC’s) was recorded in rats fed on diets contained high concentration of aflatoxins, while significantly increased count of white blood cells (WBC’s) was found in these group. Concentration of hemoglobin (Hb) and activity of serum glutamate pyruvate transaminase (SGPT) and serum glutamate oxalacetate transaminase (SGOT) were raised in the blood.