Background: The present study was conducted to evaluate the in vitro and in vivo antioxidant properties of aqueous extract of Podophyllum hexandrum. The antioxidant potential of the plant extract under in vitro situations was evaluated by using two separate methods, inhibition of superoxide radical and hydrogen peroxide radical. Carbon tetrachloride (CCl₄) is a well known toxicant and exposure to this chemical is known to induce oxidative stress and causes tissue damage by the formation of free radicals. Methods: 36 albino rats were divided into six groups of 6 animals each, all animals were allowed food and water ad libitum. Group I (control) was given olive oil, while the rest groups were injected intraperitoneally with a single dose of CCl₄ (1 ml/kg) as a 50% (v/v) solution in olive oil. Group II received CCl₄ only. Group III animals received vitamin E at a concentration of 50 mg/kg body weight and animals of groups IV, V and VI were given extract of Podophyllum hexandrum at concentration dose of 20, 30 and 50 mg/kg body weight. Antioxidant status in both kidney and lung tissues were estimated by determining the activities of antioxidative enzymes, glutathione reductase (GR), glutathione peroxidase (GPX), glutathione-S-transferase (GST) and superoxide dismutase (SOD); as well as by determining the levels of reduced glutathione (GSH) and thiobarbituric acid reactive substances (TBARS). In addition, superoxide and hydrogen peroxide radical scavenging activity of the extract was also determined. Results: Results showed that the extract possessed strong superoxide and hydrogen peroxide radical scavenging activity comparable to that of known antioxidant butylated hydroxy toluene (BHT). Our results also showed that CCl₄ caused a marked increase in TBARS levels whereas GSH, SOD, GR, GPX and GST levels were decreased in kidney and lung tissue homogenates of CCl₄ treated rats. Aqueous extract of Podophyllum hexandrum successfully prevented the alterations of these effects in the experimental animals. Conclusion: Our study demonstrated that the aqueous extract of Podophyllum hexandrum could protect the kidney and lung tissue against CCl₄ induced oxidative stress probably by increasing antioxidant defense activities.