Introduction: The extracts of the Pistacia species are known for their anti-inflammatory activity, including fruits and oil of P. atlantica. However, the inflammatory effect of the methanolic extract of P. atlantica leaves has not been studied. This work aimed at assessing the antiinflammatory and antioxidant activities of P. atlantica leaves extract in relation to phytochemical studies of flavonoids. Methods: The extract was obtained using sonication of leaves powder in 80 % methanol. The analysis of phenolic compounds was carried out using thin-layer chromatography (TLC). The antioxidant activity was evaluated using DPPH, ABTS and FRAP assays. The anti-inflammatory activity was determined by the reduction of carrageenaninduced hind paw edema in mice. Results: The TLC revealed 3 glycosylated flavonoids and gallic acid derivatives. The flavonoids identified corresponded to rutin, quercetrin and other heterosides of quercetin, kaempferol and myricetin. Total phenolics and flavonoids contents were comparable for the male and female trees. The antioxidant activity did not show a significative difference between the two sexes, except for that evaluated by the FRAP assay which was significantly greater for the male tree leaves extract. The leaves extract permitted significative reduction of the edema at h3 and 6 in a dose-dependent manner (100 and 250 mg/kg), while diclofenac used as control reduced the edema at h 1.5. This difference could be explained by the pharmacokinetic and pharmacodynamic properties of diclofenac and P. atlantica leaves compounds. Conclusion: P. atlantica has a strong anti-inflammatory activity and constitutes a potential source for the development of new treatments.