Natural plants products are one of the famous and commonly utilized remedies used in fighting diseases. This study was conducted to evaluate antioxidant activity of plants commonly used in Palestine (Urtica urens, Rumex cyprius and Borago officinalis). Free radical scavenging activity method was evaluated by using 2,2-diphenyl-1-picryl-hydrazyl-hydrate. The result show that the overall antioxidant activity of Rumex cyprius was the highest among the plants, followed by Urtica urens, and Borago officinalis; respectively. The (IC50) values of the methanolic extracts were 29.70+/-0.60mug/ml, 5.07+/-0.49mug/ml, 39.92+/- 0.52 mug/ml for Urtica urens, Rumex cyprius and Borago officinalis respectively. The results of this study revealed that these edible plants have high antioxidant activity and therefore they can provide natural sources of antioxidants and can be useful in preventing various diseases including cancer. These exhibited properties propose that such plants extracts can possibly be used as natural preservatives in the food and pharmaceutical industries and further characterization of Rumex cyprius constituents is needed.