The purpose of the present work is to study the yield of the essential oil of an aromatic and endemic species Artemisia mesatlantica. Additionally, we sought to determine the chemical composition of the essential oil produced by this species, as well as the determination of its antifungal activity against four microorganisms. Our samples are collected from a rural and mountainous area located in Middle Atlas of eastern Morocco (between Ifrane and Boulmane cities). Forty four constituents were identified by chromatographic analysis (GC and GC/MS) in the essential oil of this species, among which four are preponderant: âÂthujone, 1,8 cineole, camphene and camphor. The yield of the essential oil of Artemisia mesatlantica is 1% (mg/100g). The essential oil of Artemisia mesatlantica showed a significant antifungal activity against all four wood rot fungi. To our knowledge, this work is the first of its kind.