Seven essential oils were tested for in vitro cytotoxicity against the cancerous cell lines A-549,HEp-2 and DLA and normal BRL-3A, NRK-49F and Vero cell lines using standard MTT, SRB anddye exclusion techniques. The A-549 cell line was found to be the most susceptible to all theessential oils. The essential oils of A. nilagirica, A. calamus and O. sanctum were found to be themore active against these cells with mean CTC50 values of 17.75, 19.00 and 24.37mg/ml,respectively. The essential oil of Acorus calamus was found to be the most potent with low CTC50values against the cancerous and comparatively higher CTC50 values against the normal cell lines.Artemisia pellens and Pelargonium graveolens oils also showed potent activity. These oils meritfurther investigation to identify the active principles and nature of the anti tumor activity inanimal models.