The toxic effect of 84 essential oils was tested at different concentrations on Entamoeba histolytica. 15 of them were the most efficient. 5 of the latter were detailed to give the percentages of their components. Some families of plants have shown an homogeneity in the toxicity of their essential oils, while others, to the contrary, have presented heterogeneous amoebicidal activities. Further investigations should be made to identify amoebicidal effects of essential oils in vivo.