The essential oils obtained from Anethum graveolens, Foeniculum vulgare collected at fully-mature and flowering stages, Mentha piperita, Mentha spicata, Lavandula officinalis, Ocimum basilicum (green- and purple-leaf varieties), Origanum onites, O. vulgare, O. munitiflorum, O. majorana, Rosmarinus officinalis, Salvia officinalis, and Satureja cuneifolia, as well as the widely encountered components in essential oils (gamma-terpinene, 4-allylanisole, (-)-carvone, dihydrocarvone, D-limonene, (-)-phencone, cuminyl alcohol, cuminyl aldehyde, cuminol, trans-anethole, camphene, isoborneol, (-)-borneol, L-bornyl acetate, 2-decanol, 2-heptanol, methylheptane, farnesol, nerol, isopulegol, citral, citronellal, citronellol, geraniol, geranyl ester, linalool, linalyl oxide, linalyl ester, alpha-pinene, beta-pinene, piperitone, (-)-menthol, isomenthone, carvacrol, thymol, vanillin, and eugenol), were screened for their antiviral activity against Herpes simplex type-1 (HSV-1) and parainfluenza type-3 (PI-3). Cytotoxicity was expressed as cytopathogenic effect. Most of the oils and compounds displayed strong antiviral effects against HSV-1, ranging between 0.8 and 0.025 mu g mL(-1). However, the samples tested were less effective against PI-3, with results ranging between 1.6 and 0.2 mu g mL(-1). The essential oil of A. graveolens was the-most active. Most of the tested oils and compounds exhibited good antibacterial and antifungal effects.