Ephedra alata is an endemic Algerian plant with pharmacological potential, used for centuries in traditional medicine. Herein the antioxidant activity of E. alata was assessed in order to validate its traditional use in Algerian folk medicine for the treatment of different aliments. The antioxidant activity of its aqueous extract was evaluated by different assays including, DPPH, reducing capacity, and β-Carotene Bleaching Assays. E. alata aqueous extract seems to have moderate reducing capacity with EC50 of 578,16 μg/mL, and an average scavenging effects with respect to the DPPH radical with IC50 of the order of 276 μg/mL. However, we found that aqueous extract of E. alata possess a remarkable antioxidant activity against the bleaching of β carotene (77%). These results suggest that the extract of E. alata has a considerable capacity to react with free radicals to convert them into non-reactive species and to interrupt the chain of radical reactions. It also reflects the solubility of the antioxidant compounds of the extract in water. Compounds that possess this characteristic can be used in food systems. Obtained results suggest that aqueous extract of Ephedra alata could provide powerful natural; antioxidant, agents, to be used in the management.