Medicinal plants are the spine of long-established systems of medication all the way through the world. They are worthless, barely credible and conventional source for the remedial assortment of diseases in the appearance of medicines. The purpose of our current study was to estimate the antioxidant property of Citrullus colocynthis methanolic extract. Citrullus colocynthis belongs to family Cucurbitaceae, is a therapeutic plant conventionally used as an abortifacient and to indulgence constipation, oedema, bacterial infections, cancer and diabetes. The enthusiasm in the rear of this study was to emphasize the consequence of conventionally consumed plants as a persuasive resource of bioactive compounds. Phytochemical Screening of methanolic extract showed the occurrence of a variety of phytoconstituents that are accountable for pharmacological activities. The Antioxidant activity of methanolic extract was study spectrophotometrically by 1,1-diphenyl-2-picryl hydrazyl as well as free radical scavenging method. The results of present study revealed that the methanolic extract of Citrullus colocynthis possesses considerable antioxidant activity due to its free radical scavenging property.