In this study, the effects of Ginko biloba extract on -treated groups were divided subchronically-induced toxicity of acetaminophen (AAP) on functions of livers and kidneys of male albino rats were investigated. Subchronically into 8 groups. Animals of group1 received tap water daily for 1 week and served as controls. Animals of group 2 were treated with Ginko biloba extract (GBE) (50 mg /kg b.wt). Animals of group 3 were treated daily for 1 week with AAP (250 mg/kg b. wt.). Animals of group 4 were treated daily for 1 week with GBE (50 mg /kg b.wt) and AAP (250 mg/kg b. wt.). As for groups 5, 6, 7 and 8, they were treated experimentally as groups 1, 2, 3 and 4 but for 2 weeks. Determination of both liver and kidney functions was used as early indicators for the detection of liver damage and for evaluation of renal toxicity after exposure to the test articles. Meanwhile, serum concentration of malonedialdehyde was measured to assess the deleterious oxidative influence of AAP on the liver and kidneys. Also, the antioxidant glutathione (GSH) concentration and activities of antioxidant enzymes, glutathione peroxidase (GPx), glutathione-S-transferase (GST), catalase (CAT), and superoxide dismutase (SOD), were assayed under the present experimental conditions. The data demonstrated a significant increase in serum liver function enzymes such as aminotransferases (ALT and AST) as well as alkaline phosphatase subsequent to administration of AAP, whereas a significant decrease in GSH content and in the activities of GPx, GST, CAT, and SOD was observed after 1 and 2 weeks of treatments with this test article. The results also indicated that administration of 50 mg GBE/kg b. wt. was enough for nearly normalization of various parameters examined, which appears to be due to the protective effects of GBE on AAP-induced oxidative stress in the liver and kidneys