Monosodium glutamate (MSG) was administrated to rats at doses of 1.5 mg/kg body weight for four weeks. The liver functions, the activities of ALT and AST significantly increased in the serum on MSG administration while serum total protein and albumin significantly decreased, MSG had adverse effect on kidney functions as serum urea, serum creatinine and uric acid were significantly increased. Ginkgo biloba (80 mg/kg body weight) co-treatment with MSG, significantly reported the activities of ALT and AST in the serum were reduced to become comparable with control. Consequently, serum total protein, and albumin were significantly increased in the serum, while serum urea, serum creatinine and uric acid were significantly decrease after administration of each ginkgo biloba. Lipid peroxidation level of liver and kidney was increased on MSG administration against the control while lipid peroxidation level decreased significantly in co-treatment with ginkgo biloba. The results showed that MSG at dose 1.5 mg/kg of body weight may cause an adverse effect on the heptic and renal functions which might be due to oxidative stress induced by MSG on the liver and renal tissue. Supplement of ginkgo biloba was capable of ameliorating MSG induced oxidative stress on hepatic and renal functions.