This work had done the object of the chemical quality study and the evaluation of antibacterial and antifungal activity of the Cotula cinerea essential oil from South Morocco. The essential oils obtained by hydrodistillation of the aerial part of the plant had been analyzed by GC/FID and GC/MS. The essence of Cotula cinerea is characterized by dominance of the 3-iso-thujanol followed by Santolina triene and camphor. The antimicrobial activity of Cotula cinerea essential oils had been estimated vis-à-vis of four bacterial strains, three molds and four reference woods rot fungi. The essential oil of this species showed a strong antimicrobial power against the tested microorganisms.