Environmental pollution with arsenic (As) in croplands causes agricultural and health problems worldwide. Rice is an important crop in South Korea, and many studies have evaluated the relationship between As andglutathione (GSH) to alleviate As uptake from the soil into plants. However, information about therelationship between As and ascorbate (AsA) in rice seedlings is still limited with regard to As phytotoxicity. We therefore investigated changes in reactive oxygen species (ROS) and antioxidant levels in rice (Oryzasativa L. cv ‘Dasan’) seedlings with toxic As and/or AsA application. The exposure of rice seedlings to 15 μMAs inhibited plant growth and resulted in increased contents of superoxide, hydrogen peroxide, andmalondialdehyde, and induced As uptake by the roots and leaves. Application of AsA to As-exposedseedlings ameliorated As-induced oxidative stress by enhancing the capacity of AsA-GSH cycle in appliedplants and increasing As transfer from the roots to leaves. These results suggest that AsA applicationalleviated As-induced oxidative damage by maintaining sufficient levels of AsA and GSH.