Fumonisin B1 (FB1) is a mold metabolite produced by Fusarium species that is frequently found in corn worldwide. It is toxic to both liver and kidney. Hepatotoxicity was induced in rats by feeding them FB1 contaminated corn. Evidence of hepatotoxicity was observed after 60 days by an increase in the plasma activity of alanine aminotransferase (ALT), where that elevation reached 78 % (p = 0.000), in comparison with the control group. Treatment with milk thistle (S), or grape seeds (G) extracts or both (S+G) was found to return the ALT level back to normal. FB1, drastically depleted glutathione peroxidase (GpX) to 48%, while treatment with S,G, and S+G could elevate the GpX by 76%, 76% and 35% respectively. Lipid peroxidation represented by malondialdehyde was elevated significantly to 137%. On the other hand, the treated groups (S, G, and S+G) have altered the levels down to 47%, 42%, and 29% respectively. In addition to the hepatotoxicity of FB1, the kidney function was investigated too, where the creatinine level was elevated to 65%. The treatment by S, G and S+G lowered the level down to 16%, 15%and 2%. Serum activity of urea was significantly elevated to 30%, the treated group G could significantly reduce it to 23% while the treated groups S and S+G could not reduce that elevation in urea level. Histological examination of liver sections confirmed the serum analysis, where significant improvements were observed in all treated groups in comparison with the liver sections of rats fed on FB1. These improvements might be due to their ability to lower serum total cholesterol and low- density lipoprotein cholesterol levels as well as slowing the lipid peroxidation process by enhancing antioxidant enzyme activity.