The crude methanolic extract, ethyl acetate and butanolic fractions, tannins, saponins and polysaccharides of the marine brown alga, Padina pavonica, growing on the Algerian Mediterranean Coast were measured for antioxidant activity, using total antioxidant capacity (TAC), reducing power and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays. Total phenolic, flavonoid and proanthocyanidin contents were determined. The total phenolic, proanthocyanidin and flavonoid contents of methanolic extract were about of 2.007 ± 0.104 mg GAE/g DM, 4.611 ± 0.346 mg CE/g DM and 1.132 ± 0.091 mg CE/g DM, respectively. The total antioxidant capacity was higher (4.365 ± 0.452 mg AAE/g DM) in crude methanolic extract. 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