Considering the traditional use of A. muricata as an anthelmintic agent against human gastrointestinal parasitism and since previous phytochemical data indicate a high content of antiparasitic acetogenins in the leaves and seeds of plants from Annona genus, the aim of this work was to evaluate the in vitro anthelmintic effects of A. muricata aqueous leaf extract against eggs, infective larvae and adult forms of parasitic nematode H. contortus.