Lavandula stoechas L. from the west of Algeria were analyzed for their chemical composition, mineral content, total phenol and flavonoid contents, and also the antioxidant activity of the essential oils and methanol extract. Many essential minerals including potassium, magnesium, sodium and trace elements, such as iron, zinc, copper and manganese were determined. The total phenol and flavonoid contents in Lavandula stoechas were determined spectrophotometrically as 9.74 mg ± 0.48 gallic acid equivalents / gram of plant, and 4.615 mg ± 0.18 rutin equivalents / gram of plant for polyphenols and flavonoids respectively. The essential oils extracted by water distillation leads to extract 1.36 % dw, its composition identified by the GCâMS analysis was characterized by high proportions of α-fenchone (39.0 %), camphor (18.5 %), bornyl acetate (7.79 %), viridiflorol (4.55 %), and myrtenyl acetate (3.32 %). Our results show, in all tests of antioxidant capacity, that methanol extract has power to scavenging free radicals and reducing metals, better than Lavandula stoechas essential oils.