Amebiasis is a parasitic disease that extends worldwide and is a public health problem in developing countries. Metronidazole is the drug recommended in the treatment of amebiasis, but its contralateral effects and lack of continuity of treatment induce low efficiency, coupled with the appearance of resistant amoebic strains. Therefore, the search of new compounds with amoebicidal activity is urgent and important. In this study, we evaluated the in vitro and in vivo antiamoebic activity of the essential oil Dysphania ambrosioides (L.) Mosyakin & Clemants. It exhibited an IC₅₀ = 0.7 mg/mL against trophozoites. The oral administration of essential oil (8 mg/kg and 80 mg/kg) to hamster infected with Entamoeba histolytica reverted the infection. Ascaridole was identified as the main component of essential oil of D. ambrosioides. The identification of amoebicidal activity of Ascaridole gives support to the traditional use. Further studies with Ascaridole will be carried out to understand the mechanism involved.