The Olea europaea L. leaves represent a typical herbal drug of the Mediterranean area, commonly used in traditional medicine as vasodilatatory, hypotensive, anti-inflammatory, antirheumatic, diuretic, antipyretic and hypoglycaemic agents. In the present study, phytochemical characterization of Olea europaea L. was carried out by identifying and quantifying the main leaf polyphenols. Identification and quantification of flavonoid glycosides and secoiridoids was carried out on different extracts of Olea europaea L (Oleaceae) leaves by means of HPLC/DAD and HPLC/MS analysis, the latter interfaced to an API-Elecrospray equipment. The following polyphenols were detected in olive leaf tissue: hydroxythyrosol glucoside, hydroxythyrosol, tyrosol, elenolic acid derivative, caffeic acid, oleuropein, verbascoside, rutin, luteolin 7-O-glucoside, luteolin 4'-O-glucoside, apigenin 7-O-rutinoside and apigenin 7-O-glucoside. Antioxidant activities of an hydroalcoholic extract, both decoction and tea from Olea leaves were evaluated by means of the DPPH method (in vitro test). All the tested extracts efficiently scavenged the DPPH free radical and consequently a pharmacological use of the olive leaf tissue seems plausible