The fumigant antifungal activities of ajowan (Trachyspermum ammi), and allspice (Pimenta dioica) essential oils and their constituents were tested against three Aspergillus species: A. ochraceus, A. parasiticus, and A. niger. Ajowan essential oil demonstrated a 100% inhibition rate against these three Aspergillus species at an air concentration of 56 Ã 10â3 mg/mL. The fumigant antifungal activities of allspice essential oil against A. niger, A. ochraceus, and A. parasiticus were 100, 84.4, and 83.5%, respectively. Gas chromatography-mass spectrometry analysis led to the identification of twelve compounds in ajowan oil and six compounds in allspice oil. Of the compounds tested, thymol, carvacrol, and eugenol showed strong inhibitory activity against the three Aspergillus species. The fumigant antifungal activities of blends of the constituents identified in ajowan and allspice oils indicated that thymol and eugenol were the major contributors to the fumigant antifungal activities of ajowan and allspice oils, respectively.