Emodin (a rhubarb anthraquinone) has strong antioxidant and anticancer actions, and recent studies indicated that it reduces cellular oxidative stress induced by various insults and drugs. Cisplatin is an anticancer drug that is associated with nephrotoxicity and induces oxidative stress in cultured human kidney (HEK 293) cells. This study aimed to assess the in-vitro antioxidant properties of the emodin against cisplatin-induced oxidative stress in HEK 293 cells. Our study revealed that emodin acted as a potent free radical scavenger and provided nephroprotection against cisplatin-induced oxidative stress. Emodin as low as 0.5 µm did not decrease cell viability and restored the cisplatin-induced glutathione depletion and total antioxidant capacity in a dose-dependent manner. Emodin augmented the cisplatin-induced inhibition of antioxidant enzymes (catalase, glutathione peroxidase, glutathione S-transferase, glutathione reductase and superoxide dismutase). These results suggest that emodin has the potential to be used as an adjunct therapeutic agent in patients receiving cisplatin treatment. Copyright © 2012 John Wiley & Sons, Ltd.