The antifungal properties of Zataria multiflora Boiss. and Thymw; eriocalyx (Ronniger) Jalas essential oils were studied on growth inhibition of Aspergillw; parasiticus NRRL 2999. Minimal inhibitory (MIC) and fungicidal (MFC) and kinetics of fungal spore death as a result of exposure to the oils were studied. The oils were analyzed by GC and GCIMS and their chemical components were identified. 22 and 19 compounds were identified in Zataria multiflora Boiss. and Thymw; eriocalyx (Ronniger) Jalas essential oils respectively. Eight compounds viz; athujene, a-pinene, sabinene, myrcene, p-cymene, 1,8-cineole, cis sabinene hydrate and thymol were common in both oils but in different concentrations. The results indicated powerful antifungal properties of both oils inhibiting growth and aflatoxin production that could be applied to food as preservatives.